diff --git a/android/Images/OtherIcons/Timer.png b/android/Images/OtherIcons/Timer.png
new file mode 100644
index 0000000000..b5fb7a9f64
Binary files /dev/null and b/android/Images/OtherIcons/Timer.png differ
diff --git a/android/assets/jsons/Civ V - Gods & Kings/Speeds.json b/android/assets/jsons/Civ V - Gods & Kings/Speeds.json
new file mode 100644
index 0000000000..9c6aeba13d
--- /dev/null
+++ b/android/assets/jsons/Civ V - Gods & Kings/Speeds.json	
@@ -0,0 +1,113 @@
+[
+    {
+        "name": "Quick",
+        "modifier": 0.67,
+        "productionCostModifier": 0.67,
+        "goldCostModifier": 0.67,
+        "scienceCostModifier": 0.67,
+        "cultureCostModifier": 0.67,
+        "faithCostModifier": 0.67,
+        "improvementBuildLengthModifier": 0.67,
+        "barbarianModifier": 0.67,
+        "goldGiftModifier": 1.25,
+        "cityStateTributeScalingInterval": 5.0,
+        "goldenAgeLengthModifier": 0.80,
+        "religiousPressureAdjacentCity": 9,
+        "peaceDealDuration": 10,
+        "dealDuration": 25,
+        "startYear": -4000,
+        "turns": [
+            {"yearsPerTurn": 60, "untilTurn":  50},
+            {"yearsPerTurn": 40, "untilTurn":  80},
+            {"yearsPerTurn": 30, "untilTurn": 100},
+            {"yearsPerTurn": 20, "untilTurn": 130},
+            {"yearsPerTurn": 10, "untilTurn": 155},
+            {"yearsPerTurn":  5, "untilTurn": 195},
+            {"yearsPerTurn":  2, "untilTurn": 260},
+            {"yearsPerTurn":  1, "untilTurn": 330}
+        ]
+    },
+    {
+        "name": "Standard",
+        "modifier": 1.0,
+        "productionCostModifier": 1.0,
+        "goldCostModifier": 1.0,
+        "scienceCostModifier": 1.0,
+        "cultureCostModifier": 1.0,
+        "faithCostModifier": 1.0,
+        "improvementBuildLengthModifier": 1.0,
+        "barbarianModifier": 1.0,
+        "goldGiftModifier": 1.0,
+        "cityStateTributeScalingInterval": 6.5,
+        "goldenAgeLengthModifier": 1.0,
+        "religiousPressureAdjacentCity": 6,
+        "peaceDealDuration": 10,
+        "dealDuration": 30,
+        "startYear": -4000,
+        "turns": [
+            {"yearsPerTurn":  40, "untilTurn": 75},
+            {"yearsPerTurn":  25, "untilTurn": 135},
+            {"yearsPerTurn":  20, "untilTurn": 160},
+            {"yearsPerTurn":  10, "untilTurn": 210},
+            {"yearsPerTurn":   5, "untilTurn": 270},
+            {"yearsPerTurn":   2, "untilTurn": 320},
+            {"yearsPerTurn":   1, "untilTurn": 440},
+            {"yearsPerTurn": 0.5, "untilTurn": 500}
+        ]
+    },
+    {
+        "name": "Epic",
+        "modifier": 1.5,
+        "productionCostModifier": 1.5,
+        "goldCostModifier": 1.5,
+        "scienceCostModifier": 1.5,
+        "cultureCostModifier": 1.5,
+        "faithCostModifier": 1.5,
+        "improvementBuildLengthModifier": 1.5,
+        "barbarianModifier": 1.5,
+        "goldGiftModifier": 0.75,
+        "cityStateTributeScalingInterval": 14.0,
+        "goldenAgeLengthModifier": 1.25,
+        "religiousPressureAdjacentCity": 4,
+        "peaceDealDuration": 15,
+        "dealDuration": 45,
+        "startYear": -4000,
+        "turns": [
+            {"yearsPerTurn":  25, "untilTurn": 140},
+            {"yearsPerTurn":  15, "untilTurn": 230},
+            {"yearsPerTurn":  10, "untilTurn": 270},
+            {"yearsPerTurn":   5, "untilTurn": 360},
+            {"yearsPerTurn":   2, "untilTurn": 430},
+            {"yearsPerTurn":   1, "untilTurn": 530},
+            {"yearsPerTurn": 0.5, "untilTurn": 750}
+        ]
+    },
+    {
+        "name": "Marathon",
+        "modifier": 3.0,
+        "productionCostModifier": 3.0,
+        "goldCostModifier": 3.0,
+        "scienceCostModifier": 3.0,
+        "cultureCostModifier": 3.0,
+        "faithCostModifier": 3.0,
+        "improvementBuildLengthModifier": 3.0,
+        "barbarianModifier": 4.0,
+        "goldGiftModifier": 0.67,
+        "cityStateTributeScalingInterval": 32.0,
+        "goldenAgeLengthModifier": 2.0,
+        "religiousPressureAdjacentCity": 2,
+        "peaceDealDuration": 30,
+        "dealDuration": 90,
+        "startYear": -4000,
+        "turns": [
+            {"yearsPerTurn":   15,     "untilTurn":  100},
+            {"yearsPerTurn":   10,     "untilTurn":  400},
+            {"yearsPerTurn":    5,     "untilTurn":  570},
+            {"yearsPerTurn":    2,     "untilTurn":  771},
+            {"yearsPerTurn":    1,     "untilTurn":  900},
+            {"yearsPerTurn":  0.5,     "untilTurn": 1080},
+            {"yearsPerTurn": 0.25,     "untilTurn": 1344},
+            {"yearsPerTurn": 0.083333, "untilTurn": 1500}
+        ]
+    }
+]
diff --git a/android/assets/jsons/Civ V - Vanilla/Speeds.json b/android/assets/jsons/Civ V - Vanilla/Speeds.json
new file mode 100644
index 0000000000..9c6aeba13d
--- /dev/null
+++ b/android/assets/jsons/Civ V - Vanilla/Speeds.json	
@@ -0,0 +1,113 @@
+[
+    {
+        "name": "Quick",
+        "modifier": 0.67,
+        "productionCostModifier": 0.67,
+        "goldCostModifier": 0.67,
+        "scienceCostModifier": 0.67,
+        "cultureCostModifier": 0.67,
+        "faithCostModifier": 0.67,
+        "improvementBuildLengthModifier": 0.67,
+        "barbarianModifier": 0.67,
+        "goldGiftModifier": 1.25,
+        "cityStateTributeScalingInterval": 5.0,
+        "goldenAgeLengthModifier": 0.80,
+        "religiousPressureAdjacentCity": 9,
+        "peaceDealDuration": 10,
+        "dealDuration": 25,
+        "startYear": -4000,
+        "turns": [
+            {"yearsPerTurn": 60, "untilTurn":  50},
+            {"yearsPerTurn": 40, "untilTurn":  80},
+            {"yearsPerTurn": 30, "untilTurn": 100},
+            {"yearsPerTurn": 20, "untilTurn": 130},
+            {"yearsPerTurn": 10, "untilTurn": 155},
+            {"yearsPerTurn":  5, "untilTurn": 195},
+            {"yearsPerTurn":  2, "untilTurn": 260},
+            {"yearsPerTurn":  1, "untilTurn": 330}
+        ]
+    },
+    {
+        "name": "Standard",
+        "modifier": 1.0,
+        "productionCostModifier": 1.0,
+        "goldCostModifier": 1.0,
+        "scienceCostModifier": 1.0,
+        "cultureCostModifier": 1.0,
+        "faithCostModifier": 1.0,
+        "improvementBuildLengthModifier": 1.0,
+        "barbarianModifier": 1.0,
+        "goldGiftModifier": 1.0,
+        "cityStateTributeScalingInterval": 6.5,
+        "goldenAgeLengthModifier": 1.0,
+        "religiousPressureAdjacentCity": 6,
+        "peaceDealDuration": 10,
+        "dealDuration": 30,
+        "startYear": -4000,
+        "turns": [
+            {"yearsPerTurn":  40, "untilTurn": 75},
+            {"yearsPerTurn":  25, "untilTurn": 135},
+            {"yearsPerTurn":  20, "untilTurn": 160},
+            {"yearsPerTurn":  10, "untilTurn": 210},
+            {"yearsPerTurn":   5, "untilTurn": 270},
+            {"yearsPerTurn":   2, "untilTurn": 320},
+            {"yearsPerTurn":   1, "untilTurn": 440},
+            {"yearsPerTurn": 0.5, "untilTurn": 500}
+        ]
+    },
+    {
+        "name": "Epic",
+        "modifier": 1.5,
+        "productionCostModifier": 1.5,
+        "goldCostModifier": 1.5,
+        "scienceCostModifier": 1.5,
+        "cultureCostModifier": 1.5,
+        "faithCostModifier": 1.5,
+        "improvementBuildLengthModifier": 1.5,
+        "barbarianModifier": 1.5,
+        "goldGiftModifier": 0.75,
+        "cityStateTributeScalingInterval": 14.0,
+        "goldenAgeLengthModifier": 1.25,
+        "religiousPressureAdjacentCity": 4,
+        "peaceDealDuration": 15,
+        "dealDuration": 45,
+        "startYear": -4000,
+        "turns": [
+            {"yearsPerTurn":  25, "untilTurn": 140},
+            {"yearsPerTurn":  15, "untilTurn": 230},
+            {"yearsPerTurn":  10, "untilTurn": 270},
+            {"yearsPerTurn":   5, "untilTurn": 360},
+            {"yearsPerTurn":   2, "untilTurn": 430},
+            {"yearsPerTurn":   1, "untilTurn": 530},
+            {"yearsPerTurn": 0.5, "untilTurn": 750}
+        ]
+    },
+    {
+        "name": "Marathon",
+        "modifier": 3.0,
+        "productionCostModifier": 3.0,
+        "goldCostModifier": 3.0,
+        "scienceCostModifier": 3.0,
+        "cultureCostModifier": 3.0,
+        "faithCostModifier": 3.0,
+        "improvementBuildLengthModifier": 3.0,
+        "barbarianModifier": 4.0,
+        "goldGiftModifier": 0.67,
+        "cityStateTributeScalingInterval": 32.0,
+        "goldenAgeLengthModifier": 2.0,
+        "religiousPressureAdjacentCity": 2,
+        "peaceDealDuration": 30,
+        "dealDuration": 90,
+        "startYear": -4000,
+        "turns": [
+            {"yearsPerTurn":   15,     "untilTurn":  100},
+            {"yearsPerTurn":   10,     "untilTurn":  400},
+            {"yearsPerTurn":    5,     "untilTurn":  570},
+            {"yearsPerTurn":    2,     "untilTurn":  771},
+            {"yearsPerTurn":    1,     "untilTurn":  900},
+            {"yearsPerTurn":  0.5,     "untilTurn": 1080},
+            {"yearsPerTurn": 0.25,     "untilTurn": 1344},
+            {"yearsPerTurn": 0.083333, "untilTurn": 1500}
+        ]
+    }
+]
diff --git a/android/assets/jsons/translations/template.properties b/android/assets/jsons/translations/template.properties
index 1eed6d8f1f..d4759f8198 100644
--- a/android/assets/jsons/translations/template.properties
+++ b/android/assets/jsons/translations/template.properties
@@ -1321,6 +1321,22 @@ Eras =
 Embarked strength: [amount]† = 
 Base unit buy cost: [amount]¤ = 
 Research agreement cost: [amount]¤ = 
+Game Speeds = 
+General speed modifier: [amount]%⏳ = 
+Production cost modifier: [amount]%⚙ = 
+Gold cost modifier: [amount]%¤ = 
+Science cost modifier: [amount]%⍾ = 
+Culture cost modifier: [amount]%♪ = 
+Faith cost modifier: [amount]%☮ = 
+Improvement build length modifier: [amount]%⏳ = 
+Diplomatic deal duration: [amount] turns⏳ = 
+Gold gift influence gain modifier: [amount]%¤ = 
+City-state tribute scaling interval: [amount] turns⏳ = 
+Barbarian spawn modifier: [amount]%† = 
+Golden age length modifier: [amount]%⌣ = 
+Adjacent city religious pressure: [amount]☮ = 
+Peace deal duration: [amount] turns⏳ = 
+Start year: [comment] = 
 Pillaging this improvement yields [stats] = 
 Pillaging this improvement yields approximately [stats] = 
 
diff --git a/core/src/com/unciv/logic/BarbarianManager.kt b/core/src/com/unciv/logic/BarbarianManager.kt
index 1692271e4b..e2b57a5605 100644
--- a/core/src/com/unciv/logic/BarbarianManager.kt
+++ b/core/src/com/unciv/logic/BarbarianManager.kt
@@ -6,7 +6,6 @@ import com.unciv.json.HashMapVector2
 import com.unciv.logic.civilization.NotificationIcon
 import com.unciv.logic.map.TileInfo
 import com.unciv.logic.map.TileMap
-import com.unciv.models.metadata.GameSpeed
 import com.unciv.models.ruleset.unique.UniqueType
 import com.unciv.ui.utils.extensions.randomWeighted
 import java.util.*
@@ -288,12 +287,6 @@ class Encampment() {
         // Quicker if this camp has already spawned units
         countdown -= min(3, spawnedUnits)
 
-        countdown *= when (gameInfo.gameParameters.gameSpeed) {
-            GameSpeed.Quick -> 67
-            GameSpeed.Standard -> 100
-            GameSpeed.Epic -> 150
-            GameSpeed.Marathon -> 400 // sic!
-        }
-        countdown /= 100
+        countdown = (countdown * gameInfo.speed.barbarianModifier).toInt()
     }
 }
diff --git a/core/src/com/unciv/logic/GameInfo.kt b/core/src/com/unciv/logic/GameInfo.kt
index 3cf107771f..959a2b30cd 100644
--- a/core/src/com/unciv/logic/GameInfo.kt
+++ b/core/src/com/unciv/logic/GameInfo.kt
@@ -16,12 +16,12 @@ import com.unciv.logic.map.TileInfo
 import com.unciv.logic.map.TileMap
 import com.unciv.models.Religion
 import com.unciv.models.metadata.GameParameters
-import com.unciv.models.metadata.GameSpeed
 import com.unciv.models.ruleset.*
 import com.unciv.models.ruleset.unique.UniqueType
 import com.unciv.ui.audio.MusicMood
 import com.unciv.ui.audio.MusicTrackChooserFlags
 import java.util.*
+import kotlin.NoSuchElementException
 
 
 class GameInfo {
@@ -55,6 +55,9 @@ class GameInfo {
     @Transient
     lateinit var difficultyObject: Difficulty // Since this is static game-wide, and was taking a large part of nextTurn
 
+    @Transient
+    lateinit var speed: Speed
+
     @Transient
     lateinit var currentPlayerCiv: CivilizationInfo // this is called thousands of times, no reason to search for it with a find{} every time
 
@@ -152,40 +155,20 @@ class GameInfo {
     }
 
     private fun getEquivalentTurn(): Int {
-        val totalTurns = 500f * gameParameters.gameSpeed.modifier
+        val totalTurns = speed.numTotalTurns()
         val startPercent = ruleSet.eras[gameParameters.startingEra]!!.startPercent
-        return turns + ((totalTurns * startPercent).toInt() / 100)
-    }
-    private class YearsToTurn(
-        // enum class with lists for each value group potentially more efficient?
-        val toTurn: Int,
-        val yearInterval: Float
-    ) {
-        companion object {
-            // Best to initialize these once only
-            val marathon = listOf(YearsToTurn(100, 15f), YearsToTurn(400, 10f), YearsToTurn(570, 5f), YearsToTurn(771, 2f), YearsToTurn(900, 1f), YearsToTurn(1080, 0.5f), YearsToTurn(1344, 0.25f), YearsToTurn(1500, 0.083333f))
-            val epic     = listOf(YearsToTurn(140, 25f), YearsToTurn(230, 15f), YearsToTurn(270, 10f), YearsToTurn(360, 5f), YearsToTurn(430, 2f), YearsToTurn(530, 1f), YearsToTurn(1500, 0.5f))
-            val standard = listOf(YearsToTurn(75, 40f), YearsToTurn(135, 25f), YearsToTurn(160, 20f), YearsToTurn(210, 10f), YearsToTurn(270, 5f), YearsToTurn(320, 2f), YearsToTurn(440, 1f), YearsToTurn(500, 0.5f))
-            val quick    = listOf(YearsToTurn(50, 60f), YearsToTurn(80, 40f), YearsToTurn(100, 30f), YearsToTurn(130, 20f), YearsToTurn(155, 10f), YearsToTurn(195, 5f), YearsToTurn(260, 2f), YearsToTurn(310, 1f))
-            fun getList(gameSpeed: GameSpeed) = when (gameSpeed) {
-                GameSpeed.Marathon -> marathon
-                GameSpeed.Epic -> epic
-                GameSpeed.Standard -> standard
-                GameSpeed.Quick -> quick
-            }
-        }
+        return turns + (totalTurns * startPercent / 100)
     }
 
     fun getYear(turnOffset: Int = 0): Int {
         val turn = getEquivalentTurn() + turnOffset
-        val yearToTurnList = YearsToTurn.getList(gameParameters.gameSpeed)
-        var year: Float = -4000f
+        val yearsToTurn = speed.yearsPerTurn
+        var year = speed.startYear
         var i = 0
         var yearsPerTurn: Float
 
-        // if macros are ever added to kotlin, this is one hell of a place for em'
         while (i < turn) {
-            yearsPerTurn = yearToTurnList.firstOrNull { i < it.toTurn }?.yearInterval ?: 0.5f
+            yearsPerTurn = (yearsToTurn.firstOrNull { i < it.untilTurn }?.yearInterval ?: yearsToTurn.last().yearInterval)
             year += yearsPerTurn
             ++i
         }
@@ -431,6 +414,8 @@ class GameInfo {
 
         difficultyObject = ruleSet.difficulties[difficulty]!!
 
+        speed = ruleSet.speeds[gameParameters.speed]!!
+
         for (religion in religions.values) religion.setTransients(this)
 
         for (civInfo in civilizations) civInfo.setTransients()
diff --git a/core/src/com/unciv/logic/GameStarter.kt b/core/src/com/unciv/logic/GameStarter.kt
index 917e1e2efa..6c7a441797 100644
--- a/core/src/com/unciv/logic/GameStarter.kt
+++ b/core/src/com/unciv/logic/GameStarter.kt
@@ -46,6 +46,11 @@ object GameStarter {
         val ruleset = RulesetCache.getComplexRuleset(gameInfo.gameParameters)
         val mapGen = MapGenerator(ruleset)
 
+        // Make sure that a valid game speed is loaded (catches a base ruleset not using the default game speed)
+        if (!ruleset.speeds.containsKey(gameSetupInfo.gameParameters.speed)) {
+            gameSetupInfo.gameParameters.speed = ruleset.speeds.keys.first()
+        }
+
         if (gameSetupInfo.mapParameters.name != "") runAndMeasure("loadMap") {
             tileMap = MapSaver.loadMap(gameSetupInfo.mapFile!!)
             // Don't override the map parameters - this can include if we world wrap or not!
@@ -202,8 +207,8 @@ object GameStarter {
         val startingEra = gameInfo.gameParameters.startingEra
         val era = ruleSet.eras[startingEra]!!
         for (civInfo in gameInfo.civilizations.filter { !it.isBarbarian() }) {
-            civInfo.addGold((era.startingGold * gameInfo.gameParameters.gameSpeed.modifier).toInt())
-            civInfo.policies.addCulture((era.startingCulture * gameInfo.gameParameters.gameSpeed.modifier).toInt())
+            civInfo.addGold((era.startingGold * gameInfo.speed.goldCostModifier).toInt())
+            civInfo.policies.addCulture((era.startingCulture * gameInfo.speed.cultureCostModifier).toInt())
         }
     }
 
diff --git a/core/src/com/unciv/logic/automation/Automation.kt b/core/src/com/unciv/logic/automation/Automation.kt
index 0d9a7ee65a..d95cc2f6f1 100644
--- a/core/src/com/unciv/logic/automation/Automation.kt
+++ b/core/src/com/unciv/logic/automation/Automation.kt
@@ -193,19 +193,18 @@ object Automation {
         if (civInfo.isCityState() || civInfo.isBarbarian())
             return false
 
-        // If there are no barbarians we are not afraid
         if (civInfo.gameInfo.gameParameters.noBarbarians)
-            return false
+            return false // If there are no barbarians we are not afraid
 
-        // Very late in the game we are not afraid
-        if (civInfo.gameInfo.turns > 200 * civInfo.gameInfo.gameParameters.gameSpeed.modifier)
-            return false
+        val speed = civInfo.gameInfo.speed
+        if (civInfo.gameInfo.turns > 200 * speed.barbarianModifier)
+            return false // Very late in the game we are not afraid
 
         var multiplier = if (civInfo.gameInfo.gameParameters.ragingBarbarians) 1.3f
         else 1f // We're slightly more afraid of raging barbs
 
         // Past the early game we are less afraid
-        if (civInfo.gameInfo.turns > 120 * civInfo.gameInfo.gameParameters.gameSpeed.modifier * multiplier)
+        if (civInfo.gameInfo.turns > 120 * speed.barbarianModifier * multiplier)
             multiplier /= 2
 
         // If we have a lot of, or no cities we are not afraid
diff --git a/core/src/com/unciv/logic/city/CityReligion.kt b/core/src/com/unciv/logic/city/CityReligion.kt
index bee03ae21d..a1ad1808f5 100644
--- a/core/src/com/unciv/logic/city/CityReligion.kt
+++ b/core/src/com/unciv/logic/city/CityReligion.kt
@@ -4,7 +4,6 @@ import com.unciv.Constants
 import com.unciv.logic.civilization.NotificationIcon
 import com.unciv.models.Counter
 import com.unciv.models.Religion
-import com.unciv.models.metadata.GameSpeed
 import com.unciv.models.ruleset.unique.Unique
 import com.unciv.models.ruleset.unique.UniqueType
 import com.unciv.ui.utils.extensions.toPercent
@@ -23,14 +22,7 @@ class CityInfoReligionManager {
     private val followers: Counter<String> = Counter()
 
     @delegate:Transient
-    private val pressureFromAdjacentCities: Int by lazy {
-        when (cityInfo.civInfo.gameInfo.gameParameters.gameSpeed) {
-            GameSpeed.Quick -> 9
-            GameSpeed.Standard -> 6
-            GameSpeed.Epic -> 4
-            GameSpeed.Marathon -> 2
-        }
-    }
+    private val pressureFromAdjacentCities: Int by lazy { cityInfo.civInfo.gameInfo.speed.religiousPressureAdjacentCity }
 
     var religionThisIsTheHolyCityOf: String? = null
 
diff --git a/core/src/com/unciv/logic/civilization/CityStateFunctions.kt b/core/src/com/unciv/logic/civilization/CityStateFunctions.kt
index cfd9bee780..ed80c7c8c3 100644
--- a/core/src/com/unciv/logic/civilization/CityStateFunctions.kt
+++ b/core/src/com/unciv/logic/civilization/CityStateFunctions.kt
@@ -3,7 +3,6 @@ package com.unciv.logic.civilization
 import com.unciv.Constants
 import com.unciv.logic.automation.NextTurnAutomation
 import com.unciv.logic.civilization.diplomacy.*
-import com.unciv.models.metadata.GameSpeed
 import com.unciv.models.ruleset.Ruleset
 import com.unciv.models.ruleset.tile.ResourceSupplyList
 import com.unciv.models.ruleset.unique.Unique
@@ -134,14 +133,10 @@ class CityStateFunctions(val civInfo: CivilizationInfo) {
         // https://github.com/Gedemon/Civ5-DLL/blob/aa29e80751f541ae04858b6d2a2c7dcca454201e/CvGameCoreDLL_Expansion1/CvMinorCivAI.cpp
         // line 8681 and below
         var influenceGained = giftAmount.toFloat().pow(1.01f) / 9.8f
-        val gameProgressApproximate = min(civInfo.gameInfo.turns / (400f * civInfo.gameInfo.gameParameters.gameSpeed.modifier), 1f)
+        val speed = civInfo.gameInfo.speed
+        val gameProgressApproximate = min(civInfo.gameInfo.turns / (400f * speed.modifier), 1f)
         influenceGained *= 1 - (2/3f) * gameProgressApproximate
-        influenceGained *= when (civInfo.gameInfo.gameParameters.gameSpeed) {
-            GameSpeed.Quick -> 1.25f
-            GameSpeed.Standard -> 1f
-            GameSpeed.Epic -> 0.75f
-            GameSpeed.Marathon -> 0.67f
-        }
+        influenceGained *= speed.goldGiftModifier
         for (unique in donorCiv.getMatchingUniques(UniqueType.CityStateGoldGiftsProvideMoreInfluence))
             influenceGained *= 1f + unique.params[0].toFloat() / 100f
 
@@ -273,7 +268,7 @@ class CityStateFunctions(val civInfo: CivilizationInfo) {
 
     fun getDiplomaticMarriageCost(): Int {
         // https://github.com/Gedemon/Civ5-DLL/blob/master/CvGameCoreDLL_Expansion1/CvMinorCivAI.cpp, line 7812
-        var cost = (500 * civInfo.gameInfo.gameParameters.gameSpeed.modifier).toInt()
+        var cost = (500 * civInfo.gameInfo.speed.goldCostModifier).toInt()
         // Plus disband value of all units
         for (unit in civInfo.getCivUnits()) {
             cost += unit.baseUnit.getDisbandGold(civInfo)
@@ -393,18 +388,8 @@ class CityStateFunctions(val civInfo: CivilizationInfo) {
 
     fun goldGainedByTribute(): Int {
         // These values are close enough, linear increase throughout the game
-        var gold = when (civInfo.gameInfo.gameParameters.gameSpeed) {
-            GameSpeed.Quick -> 60
-            GameSpeed.Standard -> 50
-            GameSpeed.Epic -> 35
-            GameSpeed.Marathon -> 30
-        }
-        val turnsToIncrement = when (civInfo.gameInfo.gameParameters.gameSpeed) {
-            GameSpeed.Quick -> 5f
-            GameSpeed.Standard -> 6.5f
-            GameSpeed.Epic -> 14f
-            GameSpeed.Marathon -> 32f
-        }
+        var gold = (10 * civInfo.gameInfo.speed.goldGiftModifier).toInt() * 5 // rounding down to nearest 5
+        val turnsToIncrement = civInfo.gameInfo.speed.cityStateTributeScalingInterval
         gold += 5 * (civInfo.gameInfo.turns / turnsToIncrement).toInt()
 
         return gold
diff --git a/core/src/com/unciv/logic/civilization/CivInfoStats.kt b/core/src/com/unciv/logic/civilization/CivInfoStats.kt
index 04ee0d76de..fc26eff242 100644
--- a/core/src/com/unciv/logic/civilization/CivInfoStats.kt
+++ b/core/src/com/unciv/logic/civilization/CivInfoStats.kt
@@ -3,7 +3,6 @@ package com.unciv.logic.civilization
 import com.unciv.Constants
 import com.unciv.logic.civilization.diplomacy.RelationshipLevel
 import com.unciv.logic.map.RoadStatus
-import com.unciv.models.metadata.BASE_GAME_DURATION_TURNS
 import com.unciv.models.ruleset.BeliefType
 import com.unciv.models.ruleset.Policy
 import com.unciv.models.ruleset.tile.ResourceType
@@ -62,7 +61,7 @@ class CivInfoStats(val civInfo: CivilizationInfo) {
         val numberOfUnitsToPayFor = max(0.0, costsToPay.asSequence().drop(freeUnits).sumOf { it.toDouble() } ).toFloat()
 
         // as game progresses Maintenance cost rises
-        val turnLimit = BASE_GAME_DURATION_TURNS * civInfo.gameInfo.gameParameters.gameSpeed.modifier
+        val turnLimit = civInfo.gameInfo.speed.numTotalTurns().toFloat()
         val gameProgress = min(civInfo.gameInfo.turns / turnLimit, 1f)
 
         var cost = baseUnitCost * numberOfUnitsToPayFor * (1 + gameProgress)
diff --git a/core/src/com/unciv/logic/civilization/CivilizationInfo.kt b/core/src/com/unciv/logic/civilization/CivilizationInfo.kt
index cdee21094a..acea5e4586 100644
--- a/core/src/com/unciv/logic/civilization/CivilizationInfo.kt
+++ b/core/src/com/unciv/logic/civilization/CivilizationInfo.kt
@@ -1025,7 +1025,7 @@ class CivilizationInfo {
     fun removeFlag(flag: String) = flagsCountdown.remove(flag)
     fun hasFlag(flag: String) = flagsCountdown.contains(flag)
 
-    fun getTurnsBetweenDiplomaticVotes() = (15 * gameInfo.gameParameters.gameSpeed.modifier).toInt() // Dunno the exact calculation, hidden in Lua files
+    fun getTurnsBetweenDiplomaticVotes() = (15 * gameInfo.speed.modifier).toInt() // Dunno the exact calculation, hidden in Lua files
 
     fun getTurnsTillNextDiplomaticVote() = flagsCountdown[CivFlags.TurnsTillNextDiplomaticVote.name]
 
@@ -1115,7 +1115,7 @@ class CivilizationInfo {
     }
 
     private fun getTurnsBeforeRevolt() =
-        ((4 + Random().nextInt(3)) * max(gameInfo.gameParameters.gameSpeed.modifier, 1f)).toInt()
+        ((4 + Random().nextInt(3)) * max(gameInfo.speed.modifier, 1f)).toInt()
 
     /** Modify gold by a given amount making sure it does neither overflow nor underflow.
      * @param delta the amount to add (can be negative)
@@ -1265,7 +1265,7 @@ class CivilizationInfo {
     fun getResearchAgreementCost(): Int {
         // https://forums.civfanatics.com/resources/research-agreements-bnw.25568/
         return (
-            getEra().researchAgreementCost * gameInfo.gameParameters.gameSpeed.modifier
+            getEra().researchAgreementCost * gameInfo.speed.goldCostModifier
         ).toInt()
     }
 
@@ -1367,7 +1367,7 @@ class CivilizationInfo {
 
     fun receiveGoldGift(donorCiv: CivilizationInfo, giftAmount: Int) =
         cityStateFunctions.receiveGoldGift(donorCiv, giftAmount)
-    fun turnsForGreatPersonFromCityState(): Int = ((37 + Random().nextInt(7)) * gameInfo.gameParameters.gameSpeed.modifier).toInt()
+    fun turnsForGreatPersonFromCityState(): Int = ((37 + Random().nextInt(7)) * gameInfo.speed.modifier).toInt()
 
     fun getProtectorCivs() = cityStateFunctions.getProtectorCivs()
     fun addProtectorCiv(otherCiv: CivilizationInfo) = cityStateFunctions.addProtectorCiv(otherCiv)
diff --git a/core/src/com/unciv/logic/civilization/GoldenAgeManager.kt b/core/src/com/unciv/logic/civilization/GoldenAgeManager.kt
index c6cf293de9..c8d1d5c83e 100644
--- a/core/src/com/unciv/logic/civilization/GoldenAgeManager.kt
+++ b/core/src/com/unciv/logic/civilization/GoldenAgeManager.kt
@@ -29,7 +29,7 @@ class GoldenAgeManager {
         var turnsToGoldenAge = unmodifiedNumberOfTurns.toFloat()
         for (unique in civInfo.getMatchingUniques(UniqueType.GoldenAgeLength))
             turnsToGoldenAge *= unique.params[0].toPercent()
-        turnsToGoldenAge *= civInfo.gameInfo.gameParameters.gameSpeed.modifier
+        turnsToGoldenAge *= civInfo.gameInfo.speed.goldenAgeLengthModifier
         turnsLeftForCurrentGoldenAge += turnsToGoldenAge.toInt()
         civInfo.addNotification("You have entered a Golden Age!", "StatIcons/Happiness")
         civInfo.popupAlerts.add(PopupAlert(AlertType.GoldenAge, ""))
diff --git a/core/src/com/unciv/logic/civilization/PolicyManager.kt b/core/src/com/unciv/logic/civilization/PolicyManager.kt
index f3588c39b5..3cb39579d4 100644
--- a/core/src/com/unciv/logic/civilization/PolicyManager.kt
+++ b/core/src/com/unciv/logic/civilization/PolicyManager.kt
@@ -144,7 +144,7 @@ class PolicyManager {
         for (unique in civInfo.getMatchingUniques(UniqueType.LessPolicyCostFromCities)) cityModifier *= 1 - unique.params[0].toFloat() / 100
         for (unique in civInfo.getMatchingUniques(UniqueType.LessPolicyCost)) policyCultureCost *= unique.params[0].toPercent()
         if (civInfo.isPlayerCivilization()) policyCultureCost *= civInfo.getDifficulty().policyCostModifier
-        policyCultureCost *= civInfo.gameInfo.gameParameters.gameSpeed.modifier
+        policyCultureCost *= civInfo.gameInfo.speed.cultureCostModifier
         val cost: Int = (policyCultureCost * (1 + cityModifier)).roundToInt()
         return cost - (cost % 5)
     }
diff --git a/core/src/com/unciv/logic/civilization/QuestManager.kt b/core/src/com/unciv/logic/civilization/QuestManager.kt
index 6e832afdb1..ac3203190f 100644
--- a/core/src/com/unciv/logic/civilization/QuestManager.kt
+++ b/core/src/com/unciv/logic/civilization/QuestManager.kt
@@ -144,7 +144,7 @@ class QuestManager {
                 else
                     GLOBAL_QUEST_MIN_TURNS_BETWEEN + Random.nextInt(GLOBAL_QUEST_RAND_TURNS_BETWEEN)
 
-        globalQuestCountdown = (countdown * civInfo.gameInfo.gameParameters.gameSpeed.modifier).toInt()
+        globalQuestCountdown = (countdown * civInfo.gameInfo.speed.modifier).toInt()
     }
 
     private fun seedIndividualQuestsCountdown() {
@@ -164,7 +164,7 @@ class QuestManager {
                 else
                     INDIVIDUAL_QUEST_MIN_TURNS_BETWEEN + Random.nextInt(INDIVIDUAL_QUEST_RAND_TURNS_BETWEEN)
 
-        individualQuestCountdown[challenger.civName] = (countdown * civInfo.gameInfo.gameParameters.gameSpeed.modifier).toInt()
+        individualQuestCountdown[challenger.civName] = (countdown * civInfo.gameInfo.speed.modifier).toInt()
     }
 
     private fun tryStartNewGlobalQuest() {
@@ -905,7 +905,7 @@ class AssignedQuest(val questName: String = "",
     fun doesExpire(): Boolean = gameInfo.ruleSet.quests[questName]!!.duration > 0
     fun isExpired(): Boolean = doesExpire() && getRemainingTurns() == 0
     @Suppress("MemberVisibilityCanBePrivate")
-    fun getDuration(): Int = (gameInfo.gameParameters.gameSpeed.modifier * gameInfo.ruleSet.quests[questName]!!.duration).toInt()
+    fun getDuration(): Int = (gameInfo.speed.modifier * gameInfo.ruleSet.quests[questName]!!.duration).toInt()
     fun getRemainingTurns(): Int = max(0, (assignedOnTurn + getDuration()) - gameInfo.turns)
 
     fun getDescription(): String {
diff --git a/core/src/com/unciv/logic/civilization/ReligionManager.kt b/core/src/com/unciv/logic/civilization/ReligionManager.kt
index 28c757e34b..6d4b260a54 100644
--- a/core/src/com/unciv/logic/civilization/ReligionManager.kt
+++ b/core/src/com/unciv/logic/civilization/ReligionManager.kt
@@ -110,7 +110,7 @@ class ReligionManager {
 
         var faithCost =
             (200 + 100 * greatProphetsEarned * (greatProphetsEarned + 1) / 2f) *
-            civInfo.gameInfo.gameParameters.gameSpeed.modifier
+            civInfo.gameInfo.speed.faithCostModifier
 
         for (unique in civInfo.getMatchingUniques(UniqueType.FaithCostOfGreatProphetChange))
             faithCost *= unique.params[0].toPercent()
diff --git a/core/src/com/unciv/logic/civilization/TechManager.kt b/core/src/com/unciv/logic/civilization/TechManager.kt
index 4220e5508a..11e79b0e20 100644
--- a/core/src/com/unciv/logic/civilization/TechManager.kt
+++ b/core/src/com/unciv/logic/civilization/TechManager.kt
@@ -86,7 +86,7 @@ class TechManager {
         var techCost = getRuleset().technologies[techName]!!.cost.toFloat()
         if (civInfo.isPlayerCivilization())
             techCost *= civInfo.getDifficulty().researchCostModifier
-        techCost *= civInfo.gameInfo.gameParameters.gameSpeed.modifier
+        techCost *= civInfo.gameInfo.speed.scienceCostModifier
         val techsResearchedKnownCivs = civInfo.getKnownCivs()
                 .count { it.isMajorCiv() && it.tech.isResearched(techName) }
         val undefeatedCivs = civInfo.gameInfo.civilizations
@@ -132,13 +132,13 @@ class TechManager {
         val tech = getRuleset().technologies[techName]!!
         if (tech.uniqueObjects.any { it.type == UniqueType.OnlyAvailableWhen && !it.conditionalsApply(civInfo) })
             return false
-        
+
         if (tech.getMatchingUniques(UniqueType.IncompatibleWith).any { isResearched(it.params[0]) })
             return false
-        
+
         if (isResearched(tech.name) && !tech.isContinuallyResearchable())
             return false
-        
+
         return tech.prerequisites.all { isResearched(it) }
     }
 
@@ -167,7 +167,7 @@ class TechManager {
 
     fun getScienceFromGreatScientist(): Int {
         // https://civilization.fandom.com/wiki/Great_Scientist_(Civ5)
-        return (scienceOfLast8Turns.sum() * civInfo.gameInfo.gameParameters.gameSpeed.modifier).toInt()
+        return (scienceOfLast8Turns.sum() * civInfo.gameInfo.speed.scienceCostModifier).toInt()
     }
 
     private fun addCurrentScienceToScienceOfLast8Turns() {
diff --git a/core/src/com/unciv/logic/map/MapUnit.kt b/core/src/com/unciv/logic/map/MapUnit.kt
index ffac2e530b..35a94756f4 100644
--- a/core/src/com/unciv/logic/map/MapUnit.kt
+++ b/core/src/com/unciv/logic/map/MapUnit.kt
@@ -959,10 +959,15 @@ class MapUnit {
 
         val gainedStats = Stats()
         for (unique in civInfo.getMatchingUniques(UniqueType.ProvidesGoldWheneverGreatPersonExpended)) {
-            gainedStats.gold += (100 * civInfo.gameInfo.gameParameters.gameSpeed.modifier).toInt()
+            gainedStats.gold += (100 * civInfo.gameInfo.speed.goldCostModifier).toInt()
         }
         for (unique in civInfo.getMatchingUniques(UniqueType.ProvidesStatsWheneverGreatPersonExpended)) {
-            gainedStats.add(unique.stats)
+            val uniqueStats = unique.stats
+            val speedModifiers = civInfo.gameInfo.speed.statCostModifiers
+            for (stat in uniqueStats) {
+                uniqueStats[stat.key] = stat.value * speedModifiers[stat.key]!!
+            }
+            gainedStats.add(uniqueStats)
         }
 
         if (gainedStats.isEmpty()) return
@@ -1030,7 +1035,7 @@ class MapUnit {
             .forEach { it.questManager.barbarianCampCleared(civInfo, tile.position) }
 
         var goldGained =
-            civInfo.getDifficulty().clearBarbarianCampReward * civInfo.gameInfo.gameParameters.gameSpeed.modifier
+            civInfo.getDifficulty().clearBarbarianCampReward * civInfo.gameInfo.speed.goldCostModifier
         if (civInfo.hasUnique(UniqueType.TripleGoldFromEncampmentsAndCities))
             goldGained *= 3f
 
diff --git a/core/src/com/unciv/logic/trade/TradeEvaluation.kt b/core/src/com/unciv/logic/trade/TradeEvaluation.kt
index 98aaafbc3d..72b2cf06c1 100644
--- a/core/src/com/unciv/logic/trade/TradeEvaluation.kt
+++ b/core/src/com/unciv/logic/trade/TradeEvaluation.kt
@@ -118,7 +118,7 @@ class TradeEvaluation {
 
             TradeType.Technology -> // Currently unused
                 return (sqrt(civInfo.gameInfo.ruleSet.technologies[offer.name]!!.cost.toDouble())
-                        * civInfo.gameInfo.gameParameters.gameSpeed.modifier).toInt() * 20
+                        * civInfo.gameInfo.speed.scienceCostModifier).toInt() * 20
             TradeType.Introduction -> return introductionValue(civInfo.gameInfo.ruleSet)
             TradeType.WarDeclaration -> {
                 val civToDeclareWarOn = civInfo.gameInfo.getCivilization(offer.name)
diff --git a/core/src/com/unciv/logic/trade/TradeOffer.kt b/core/src/com/unciv/logic/trade/TradeOffer.kt
index 9909c4cafc..45748aa1a0 100644
--- a/core/src/com/unciv/logic/trade/TradeOffer.kt
+++ b/core/src/com/unciv/logic/trade/TradeOffer.kt
@@ -2,7 +2,7 @@ package com.unciv.logic.trade
 
 import com.unciv.Constants
 import com.unciv.UncivGame
-import com.unciv.models.metadata.GameSpeed
+import com.unciv.models.ruleset.Speed
 import com.unciv.models.translations.tr
 import com.unciv.ui.utils.Fonts
 import com.unciv.logic.trade.TradeType.TradeTypeNumberType
@@ -13,13 +13,12 @@ data class TradeOffer(val name: String, val type: TradeType, var amount: Int = 1
         name: String,
         type: TradeType,
         amount: Int = 1,
-        gameSpeed: GameSpeed = UncivGame.Current.gameInfo!!.gameParameters.gameSpeed
+        speed: Speed = UncivGame.Current.gameInfo!!.speed
     ) : this(name, type, amount, duration = -1) {
         duration = when {
             type.isImmediate -> -1 // -1 for offers that are immediate (e.g. gold transfer)
-            name == Constants.peaceTreaty -> 10
-            gameSpeed == GameSpeed.Quick -> 25
-            else -> (30 * gameSpeed.modifier).toInt()
+            name == Constants.peaceTreaty -> speed.peaceDealDuration
+            else -> speed.dealDuration
         }
     }
 
diff --git a/core/src/com/unciv/models/ModConstants.kt b/core/src/com/unciv/models/ModConstants.kt
index d329c7a9f5..33848a1b16 100644
--- a/core/src/com/unciv/models/ModConstants.kt
+++ b/core/src/com/unciv/models/ModConstants.kt
@@ -6,9 +6,9 @@ class ModConstants {
     var maxXPfromBarbarians = 30
 
     // Formula for city Strength:
-    // Strength = baseStrength + strengthPerPop + strengthFromTiles + 
-    //            ((%techs * multiplier) ^ exponent) * fullMultiplier + 
-    //            (garrisonBonus * garrisonUnitStrength * garrisonUnitHealth/100) + 
+    // Strength = baseStrength + strengthPerPop + strengthFromTiles +
+    //            ((%techs * multiplier) ^ exponent) * fullMultiplier +
+    //            (garrisonBonus * garrisonUnitStrength * garrisonUnitHealth/100) +
     //            defensiveBuildingStrength
     // where %techs is the percentage of techs in the tech tree that are complete
     // If no techs exist in this ruleset, %techs = 0.5 (=50%)
@@ -18,10 +18,10 @@ class ModConstants {
     var cityStrengthFromTechsExponent = 2.8
     var cityStrengthFromTechsFullMultiplier = 1.0
     var cityStrengthFromGarrison = 0.2
- 
+
     // Formula for Unit Supply:
     // Supply = unitSupplyBase (difficulties.json)
-    //          unitSupplyPerCity * amountOfCities + (difficulties.json) 
+    //          unitSupplyPerCity * amountOfCities + (difficulties.json)
     //          unitSupplyPerPopulation * amountOfPopulationInAllCities
     // unitSupplyBase and unitSupplyPerCity can be found in difficulties.json
     // unitSupplyBase, unitSupplyPerCity and unitSupplyPerPopulation can also be increased through uniques
@@ -38,7 +38,7 @@ class ModConstants {
     class UnitUpgradeCost {
         val base = 10f
         val perProduction = 2f
-        val eraMultiplier = 0f  // 0.3 in Civ5 cpp sources but 0 in xml 
+        val eraMultiplier = 0f  // 0.3 in Civ5 cpp sources but 0 in xml
         val exponent = 1f
         val roundTo = 5
     }
diff --git a/core/src/com/unciv/models/metadata/GameParameters.kt b/core/src/com/unciv/models/metadata/GameParameters.kt
index 29ace901ad..f523459fbf 100644
--- a/core/src/com/unciv/models/metadata/GameParameters.kt
+++ b/core/src/com/unciv/models/metadata/GameParameters.kt
@@ -1,6 +1,7 @@
 package com.unciv.models.metadata
 
 import com.unciv.logic.civilization.PlayerType
+import com.unciv.models.ruleset.Speed
 
 enum class BaseRuleset(val fullName:String){
     Civ_V_Vanilla("Civ V - Vanilla"),
@@ -9,7 +10,7 @@ enum class BaseRuleset(val fullName:String){
 
 class GameParameters { // Default values are the default new game
     var difficulty = "Prince"
-    var gameSpeed = GameSpeed.Standard
+    var speed = Speed.DEFAULT
     var players = ArrayList<Player>().apply {
         add(Player().apply { playerType = PlayerType.Human })
         for (i in 1..3) add(Player())
@@ -22,20 +23,20 @@ class GameParameters { // Default values are the default new game
     var godMode = false
     var nuclearWeaponsEnabled = true
     var religionEnabled = false
-    
-    var victoryTypes: ArrayList<String> = arrayListOf()  
+
+    var victoryTypes: ArrayList<String> = arrayListOf()
     var startingEra = "Ancient era"
 
     var isOnlineMultiplayer = false
     var baseRuleset: String = BaseRuleset.Civ_V_GnK.fullName
     var mods = LinkedHashSet<String>()
-    
+
     var maxTurns = 500
 
     fun clone(): GameParameters {
         val parameters = GameParameters()
         parameters.difficulty = difficulty
-        parameters.gameSpeed = gameSpeed
+        parameters.speed = speed
         parameters.players = ArrayList(players)
         parameters.numberOfCityStates = numberOfCityStates
         parameters.noBarbarians = noBarbarians
@@ -54,7 +55,7 @@ class GameParameters { // Default values are the default new game
 
     // For debugging and GameStarter console output
     override fun toString() = sequence {
-            yield("$difficulty $gameSpeed $startingEra")
+            yield("$difficulty $speed $startingEra")
             yield("${players.count { it.playerType == PlayerType.Human }} ${PlayerType.Human}")
             yield("${players.count { it.playerType == PlayerType.AI }} ${PlayerType.AI}")
             yield("$numberOfCityStates CS")
@@ -69,8 +70,8 @@ class GameParameters { // Default values are the default new game
             yield(baseRuleset)
             yield(if (mods.isEmpty()) "no mods" else mods.joinToString(",", "mods=(", ")", 6) )
         }.joinToString(prefix = "(", postfix = ")")
-    
+
     fun getModsAndBaseRuleset(): HashSet<String> {
         return mods.toHashSet().apply { add(baseRuleset) }
     }
-}
\ No newline at end of file
+}
diff --git a/core/src/com/unciv/models/metadata/GameSpeed.kt b/core/src/com/unciv/models/metadata/GameSpeed.kt
deleted file mode 100644
index 34ad815f67..0000000000
--- a/core/src/com/unciv/models/metadata/GameSpeed.kt
+++ /dev/null
@@ -1,14 +0,0 @@
-package com.unciv.models.metadata
-
-const val BASE_GAME_DURATION_TURNS = 500f
-
-/** Game speed
- *
- *  @param modifier cost modifier
- * */
-enum class GameSpeed(val modifier: Float) {
-    Quick(0.67f),
-    Standard(1f),
-    Epic(1.5f),
-    Marathon(3f);
-}
\ No newline at end of file
diff --git a/core/src/com/unciv/models/ruleset/Building.kt b/core/src/com/unciv/models/ruleset/Building.kt
index b09822ffc1..005ddfaa5e 100644
--- a/core/src/com/unciv/models/ruleset/Building.kt
+++ b/core/src/com/unciv/models/ruleset/Building.kt
@@ -354,7 +354,7 @@ class Building : RulesetStatsObject(), INonPerpetualConstruction {
                 civInfo.gameInfo.getDifficulty().aiBuildingCostModifier
         }
 
-        productionCost *= civInfo.gameInfo.gameParameters.gameSpeed.modifier
+        productionCost *= civInfo.gameInfo.speed.productionCostModifier
         return productionCost.toInt()
     }
 
diff --git a/core/src/com/unciv/models/ruleset/Ruleset.kt b/core/src/com/unciv/models/ruleset/Ruleset.kt
index ed2bf7f5c2..5af736a3fc 100644
--- a/core/src/com/unciv/models/ruleset/Ruleset.kt
+++ b/core/src/com/unciv/models/ruleset/Ruleset.kt
@@ -84,6 +84,7 @@ class Ruleset {
     val buildings = LinkedHashMap<String, Building>()
     val difficulties = LinkedHashMap<String, Difficulty>()
     val eras = LinkedHashMap<String, Era>()
+    val speeds = LinkedHashMap<String, Speed>()
     var globalUniques = GlobalUniques()
     val nations = LinkedHashMap<String, Nation>()
     val policies = LinkedHashMap<String, Policy>()
@@ -123,6 +124,7 @@ class Ruleset {
         for (buildingToRemove in ruleset.modOptions.buildingsToRemove) buildings.remove(buildingToRemove)
         difficulties.putAll(ruleset.difficulties)
         eras.putAll(ruleset.eras)
+        speeds.putAll(ruleset.speeds)
         globalUniques = GlobalUniques().apply { uniques.addAll(globalUniques.uniques); uniques.addAll(ruleset.globalUniques.uniques) }
         nations.putAll(ruleset.nations)
         for (nationToRemove in ruleset.modOptions.nationsToRemove) nations.remove(nationToRemove)
@@ -152,6 +154,7 @@ class Ruleset {
         buildings.clear()
         difficulties.clear()
         eras.clear()
+        speeds.clear()
         globalUniques = GlobalUniques()
         mods.clear()
         nations.clear()
@@ -176,6 +179,7 @@ class Ruleset {
             buildings.values.asSequence() +
             //difficulties is only INamed
             eras.values.asSequence() +
+            speeds.values.asSequence() +
             sequenceOf(globalUniques) +
             nations.values.asSequence() +
             policies.values.asSequence() +
@@ -245,6 +249,11 @@ class Ruleset {
         // Using map{} sidesteps this problem
         eras.map { it.value }.withIndex().forEach { it.value.eraNumber = it.index }
 
+        val speedsFile = folderHandle.child("Speeds.json")
+        if (speedsFile.exists()) {
+            speeds += createHashmap(json().fromJsonFile(Array<Speed>::class.java, speedsFile))
+        }
+
         val unitTypesFile = folderHandle.child("UnitTypes.json")
         if (unitTypesFile.exists()) unitTypes += createHashmap(json().fromJsonFile(Array<UnitType>::class.java, unitTypesFile))
 
@@ -343,6 +352,10 @@ class Ruleset {
             if (victories.isEmpty()) {
                 victories.putAll(RulesetCache.getVanillaRuleset().victories)
             }
+
+            if (speeds.isEmpty()) {
+                speeds.putAll(RulesetCache.getVanillaRuleset().speeds)
+            }
         }
 
         debug("Loading ruleset - %sms", System.currentTimeMillis() - gameBasicsStartTime)
@@ -795,6 +808,13 @@ class Ruleset {
             checkUniques(era, lines, rulesetSpecific, forOptionsPopup)
         }
 
+        for (speed in speeds.values) {
+            if (speed.modifier < 0f)
+                lines += "Negative speed modifier for game speed ${speed.name}"
+            if (speed.yearsPerTurn.isEmpty())
+                lines += "Empty turn increment list for game speed ${speed.name}"
+        }
+
         for (belief in beliefs.values) {
             checkUniques(belief, lines, rulesetSpecific, forOptionsPopup)
         }
diff --git a/core/src/com/unciv/models/ruleset/Speed.kt b/core/src/com/unciv/models/ruleset/Speed.kt
new file mode 100644
index 0000000000..949e2a815a
--- /dev/null
+++ b/core/src/com/unciv/models/ruleset/Speed.kt
@@ -0,0 +1,83 @@
+package com.unciv.models.ruleset
+
+import com.unciv.models.ruleset.unique.UniqueTarget
+import com.unciv.models.stats.Stat
+import com.unciv.models.translations.tr
+import com.unciv.ui.civilopedia.FormattedLine
+import com.unciv.ui.utils.Fonts
+import kotlin.math.abs
+
+class Speed : RulesetObject() {
+    var modifier: Float = 1f
+    var goldCostModifier: Float = modifier
+    var productionCostModifier: Float = modifier
+    var scienceCostModifier: Float = modifier
+    var cultureCostModifier: Float = modifier
+    var faithCostModifier: Float = modifier
+    var goldGiftModifier: Float = modifier
+    var cityStateTributeScalingInterval: Float = 6.5f
+    var barbarianModifier: Float = modifier
+    var improvementBuildLengthModifier: Float = modifier
+    var goldenAgeLengthModifier: Float = modifier
+    var religiousPressureAdjacentCity: Int = 6
+    var peaceDealDuration: Int = 10
+    var dealDuration: Int = 30
+    var startYear: Float = -4000f
+    var turns: ArrayList<HashMap<String, Float>> = ArrayList()
+
+    val yearsPerTurn: ArrayList<YearsPerTurn> by lazy {
+        ArrayList<YearsPerTurn>().apply {
+            turns.forEach { this.add(YearsPerTurn(it["yearsPerTurn"]!!, it["untilTurn"]!!.toInt())) }
+        }
+    }
+
+    val statCostModifiers: HashMap<Stat, Float> by lazy {
+        HashMap<Stat, Float>().apply {
+            this[Stat.Faith] = 1f;
+            this[Stat.Production] = productionCostModifier;
+            this[Stat.Gold] = goldCostModifier;
+            this[Stat.Science] = scienceCostModifier;
+            this[Stat.Faith] = faithCostModifier;
+            this[Stat.Happiness] = 1f;
+        }
+    }
+
+    companion object {
+        const val DEFAULT: String = "Quick"
+        const val DEFAULTFORSIMULATION: String = "Standard"
+    }
+
+    override fun getUniqueTarget(): UniqueTarget = UniqueTarget.Speed
+
+    override fun makeLink(): String = "GameSpeed/$name"
+    override fun getCivilopediaTextHeader() = FormattedLine(name, header = 2)
+    override fun getCivilopediaTextLines(ruleset: Ruleset) = sequence {
+        yield(FormattedLine("General speed modifier: [${modifier * 100}]%${Fonts.turn}"))
+        yield(FormattedLine("Production cost modifier: [${productionCostModifier * 100}]%${Fonts.production}"))
+        yield(FormattedLine("Gold cost modifier: [${goldCostModifier * 100}]%${Fonts.gold}"))
+        yield(FormattedLine("Science cost modifier: [${scienceCostModifier * 100}]%${Fonts.science}"))
+        yield(FormattedLine("Culture cost modifier: [${cultureCostModifier * 100}]%${Fonts.culture}"))
+        yield(FormattedLine("Faith cost modifier: [${faithCostModifier * 100}]%${Fonts.faith}"))
+        yield(FormattedLine("Improvement build length modifier: [${improvementBuildLengthModifier * 100}]%${Fonts.turn}"))
+        yield(FormattedLine("Diplomatic deal duration: [$dealDuration] turns${Fonts.turn}"))
+        yield(FormattedLine("Gold gift influence gain modifier: [${goldGiftModifier * 100}]%${Fonts.gold}"))
+        yield(FormattedLine("City-state tribute scaling interval: [${cityStateTributeScalingInterval}] turns${Fonts.turn}"))
+        yield(FormattedLine("Barbarian spawn modifier: [${barbarianModifier * 100}]%${Fonts.strength}"))
+        yield(FormattedLine("Golden age length modifier: [${goldenAgeLengthModifier * 100}]%${Fonts.happiness}"))
+        yield(FormattedLine("Adjacent city religious pressure: [$religiousPressureAdjacentCity]${Fonts.faith}"))
+        yield(FormattedLine("Peace deal duration: [$peaceDealDuration] turns${Fonts.turn}"))
+        yield(FormattedLine("Start year: " + ("[${abs(startYear).toInt()}] " + (if (startYear < 0) "BC" else "AD")).tr()))
+    }.toList()
+
+    fun numTotalTurns(): Int = yearsPerTurn.last().untilTurn
+}
+
+class YearsPerTurn {
+    var yearInterval: Float = 0f
+    var untilTurn: Int = 0
+
+    constructor(yearsPerTurn: Float, turnsPerIncrement: Int) {
+        this.yearInterval = yearsPerTurn
+        this.untilTurn = turnsPerIncrement
+    }
+}
diff --git a/core/src/com/unciv/models/ruleset/tile/TileImprovement.kt b/core/src/com/unciv/models/ruleset/tile/TileImprovement.kt
index 7ab86606a6..adc56c8d05 100644
--- a/core/src/com/unciv/models/ruleset/tile/TileImprovement.kt
+++ b/core/src/com/unciv/models/ruleset/tile/TileImprovement.kt
@@ -31,7 +31,7 @@ class TileImprovement : RulesetStatsObject() {
     fun getTurnsToBuild(civInfo: CivilizationInfo, unit: MapUnit): Int {
         val state = StateForConditionals(civInfo, unit = unit)
         return unit.getMatchingUniques(UniqueType.TileImprovementTime, state, checkCivInfoUniques = true)
-            .fold(turnsToBuild.toFloat() * civInfo.gameInfo.gameParameters.gameSpeed.modifier) { it, unique ->
+            .fold(turnsToBuild.toFloat() * civInfo.gameInfo.speed.improvementBuildLengthModifier) { it, unique ->
                 it * unique.params[0].toPercent()
             }.roundToInt()
             .coerceAtLeast(1)
diff --git a/core/src/com/unciv/models/ruleset/unique/UniqueTriggerActivation.kt b/core/src/com/unciv/models/ruleset/unique/UniqueTriggerActivation.kt
index 4e5bb82502..90d46efc6b 100644
--- a/core/src/com/unciv/models/ruleset/unique/UniqueTriggerActivation.kt
+++ b/core/src/com/unciv/models/ruleset/unique/UniqueTriggerActivation.kt
@@ -339,7 +339,7 @@ object UniqueTriggerActivation {
 
                 val foundStatAmount =
                     (tileBasedRandom.nextInt(unique.params[0].toInt(), unique.params[1].toInt()) *
-                            civInfo.gameInfo.gameParameters.gameSpeed.modifier
+                            civInfo.gameInfo.speed.statCostModifiers[stat]!!
                             ).toInt()
 
                 civInfo.addStat(
diff --git a/core/src/com/unciv/models/ruleset/unique/UniqueType.kt b/core/src/com/unciv/models/ruleset/unique/UniqueType.kt
index 17e1c79952..8e4742e4e1 100644
--- a/core/src/com/unciv/models/ruleset/unique/UniqueType.kt
+++ b/core/src/com/unciv/models/ruleset/unique/UniqueType.kt
@@ -20,6 +20,7 @@ enum class UniqueTarget(val inheritsFrom: UniqueTarget? = null) {
     // Civilization-specific
     Nation(Global),
     Era(Global),
+    Speed(Global),
     Tech(Global),
     Policy(Global),
     FounderBelief(Global),
diff --git a/core/src/com/unciv/models/ruleset/unit/BaseUnit.kt b/core/src/com/unciv/models/ruleset/unit/BaseUnit.kt
index b9c4aa8c8f..17dac036a7 100644
--- a/core/src/com/unciv/models/ruleset/unit/BaseUnit.kt
+++ b/core/src/com/unciv/models/ruleset/unit/BaseUnit.kt
@@ -253,7 +253,7 @@ class BaseUnit : RulesetObject(), INonPerpetualConstruction {
                 civInfo.getDifficulty().unitCostModifier
             else
                 civInfo.gameInfo.getDifficulty().aiUnitCostModifier
-        productionCost *= civInfo.gameInfo.gameParameters.gameSpeed.modifier
+        productionCost *= civInfo.gameInfo.speed.productionCostModifier
         return productionCost.toInt()
     }
 
diff --git a/core/src/com/unciv/models/translations/TranslationFileWriter.kt b/core/src/com/unciv/models/translations/TranslationFileWriter.kt
index 613f507725..336506f336 100644
--- a/core/src/com/unciv/models/translations/TranslationFileWriter.kt
+++ b/core/src/com/unciv/models/translations/TranslationFileWriter.kt
@@ -456,6 +456,7 @@ object TranslationFileWriter {
                     "Buildings" -> emptyArray<Building>().javaClass
                     "Difficulties" -> emptyArray<Difficulty>().javaClass
                     "Eras" -> emptyArray<Era>().javaClass
+                    "Speeds" -> emptyArray<Speed>().javaClass
                     "GlobalUniques" -> GlobalUniques().javaClass
                     "Nations" -> emptyArray<Nation>().javaClass
                     "Policies" -> emptyArray<PolicyBranch>().javaClass
diff --git a/core/src/com/unciv/ui/civilopedia/CivilopediaCategories.kt b/core/src/com/unciv/ui/civilopedia/CivilopediaCategories.kt
index 9f35579d8d..f4c25f803b 100644
--- a/core/src/com/unciv/ui/civilopedia/CivilopediaCategories.kt
+++ b/core/src/com/unciv/ui/civilopedia/CivilopediaCategories.kt
@@ -188,6 +188,11 @@ enum class CivilopediaCategories (
         getImage = null,
         KeyCharAndCode('D'),
         "OtherIcons/Tyrannosaurus"
+    ),
+    Speed ("Speeds", false,
+        getImage = null,
+        KeyCharAndCode('S'),
+        "OtherIcons/Timer"
     );
 
     fun getByOffset(offset: Int) = values()[(ordinal + count + offset) % count]
diff --git a/core/src/com/unciv/ui/civilopedia/CivilopediaScreen.kt b/core/src/com/unciv/ui/civilopedia/CivilopediaScreen.kt
index 5d2d5c5994..7ea8a830e2 100644
--- a/core/src/com/unciv/ui/civilopedia/CivilopediaScreen.kt
+++ b/core/src/com/unciv/ui/civilopedia/CivilopediaScreen.kt
@@ -213,6 +213,7 @@ class CivilopediaScreen(
                 CivilopediaCategories.Belief -> (ruleset.beliefs.values.asSequence() +
                         Belief.getCivilopediaReligionEntry(ruleset)).toList()
                 CivilopediaCategories.Era -> ruleset.eras.values
+                CivilopediaCategories.Speed -> ruleset.speeds.values
             }
 
         for (loopCategory in CivilopediaCategories.values()) {
diff --git a/core/src/com/unciv/ui/newgamescreen/GameOptionsTable.kt b/core/src/com/unciv/ui/newgamescreen/GameOptionsTable.kt
index f9d3cd2b5b..fdfefe01a4 100644
--- a/core/src/com/unciv/ui/newgamescreen/GameOptionsTable.kt
+++ b/core/src/com/unciv/ui/newgamescreen/GameOptionsTable.kt
@@ -1,13 +1,8 @@
 package com.unciv.ui.newgamescreen
 
-import com.badlogic.gdx.Gdx
-import com.badlogic.gdx.scenes.scene2d.ui.CheckBox
-import com.badlogic.gdx.scenes.scene2d.ui.Label
 import com.badlogic.gdx.scenes.scene2d.ui.Table
 import com.unciv.UncivGame
 import com.unciv.logic.civilization.CityStateType
-import com.unciv.logic.multiplayer.OnlineMultiplayer
-import com.unciv.models.metadata.GameSpeed
 import com.unciv.models.ruleset.RulesetCache
 import com.unciv.models.ruleset.unique.UniqueType
 import com.unciv.models.translations.tr
@@ -15,7 +10,6 @@ import com.unciv.ui.audio.MusicMood
 import com.unciv.ui.audio.MusicTrackChooserFlags
 import com.unciv.ui.images.ImageGetter
 import com.unciv.ui.multiplayer.MultiplayerHelpers
-import com.unciv.ui.popup.Popup
 import com.unciv.ui.popup.ToastPopup
 import com.unciv.ui.utils.BaseScreen
 import com.unciv.ui.utils.UncivSlider
@@ -224,8 +218,8 @@ class GameOptionsTable(
     }
 
     private fun Table.addGameSpeedSelectBox() {
-        addSelectBox("{Game Speed}:", GameSpeed.values().map { it.name }, gameParameters.gameSpeed.name)
-        { gameParameters.gameSpeed = GameSpeed.valueOf(it); null }
+        addSelectBox("{Game Speed}:", ruleset.speeds.values.map { it.name }, gameParameters.speed)
+        { gameParameters.speed = it; null }
     }
 
     private fun Table.addEraSelectBox() {
diff --git a/core/src/com/unciv/ui/worldscreen/unit/UnitActions.kt b/core/src/com/unciv/ui/worldscreen/unit/UnitActions.kt
index 5209c2769e..41f912c496 100644
--- a/core/src/com/unciv/ui/worldscreen/unit/UnitActions.kt
+++ b/core/src/com/unciv/ui/worldscreen/unit/UnitActions.kt
@@ -518,7 +518,7 @@ object UnitActions {
                     action = {
                         tile.getCity()!!.cityConstructions.apply {
                             //http://civilization.wikia.com/wiki/Great_engineer_(Civ5)
-                            addProductionPoints(((300 + 30 * tile.getCity()!!.population.population) * unit.civInfo.gameInfo.gameParameters.gameSpeed.modifier).toInt())
+                            addProductionPoints(((300 + 30 * tile.getCity()!!.population.population) * unit.civInfo.gameInfo.speed.productionCostModifier).toInt())
                             constructIfEnough()
                         }
 
@@ -539,7 +539,7 @@ object UnitActions {
 
                 //http://civilization.wikia.com/wiki/Great_engineer_(Civ5)
                 val productionPointsToAdd = min(
-                    (300 + 30 * tile.getCity()!!.population.population) * unit.civInfo.gameInfo.gameParameters.gameSpeed.modifier,
+                    (300 + 30 * tile.getCity()!!.population.population) * unit.civInfo.gameInfo.speed.productionCostModifier,
                     cityConstructions.getRemainingWork(cityConstructions.currentConstructionFromQueue).toFloat() - 1
                 ).toInt()
                 if (productionPointsToAdd <= 0) continue
@@ -563,7 +563,7 @@ object UnitActions {
                 actionList += UnitAction(UnitActionType.ConductTradeMission,
                     action = {
                         // http://civilization.wikia.com/wiki/Great_Merchant_(Civ5)
-                        var goldEarned = (350 + 50 * unit.civInfo.getEraNumber()) * unit.civInfo.gameInfo.gameParameters.gameSpeed.modifier
+                        var goldEarned = (350 + 50 * unit.civInfo.getEraNumber()) * unit.civInfo.gameInfo.speed.goldCostModifier
                         for (goldUnique in unit.civInfo.getMatchingUniques(UniqueType.PercentGoldFromTradeMissions))
                             goldEarned *= goldUnique.params[0].toPercent()
                         unit.civInfo.addGold(goldEarned.toInt())
diff --git a/desktop/src/com/unciv/app/desktop/ConsoleLauncher.kt b/desktop/src/com/unciv/app/desktop/ConsoleLauncher.kt
index c96a0bb26d..4afaa50c34 100644
--- a/desktop/src/com/unciv/app/desktop/ConsoleLauncher.kt
+++ b/desktop/src/com/unciv/app/desktop/ConsoleLauncher.kt
@@ -11,12 +11,12 @@ import com.unciv.logic.map.MapSize
 import com.unciv.logic.map.MapSizeNew
 import com.unciv.models.metadata.GameParameters
 import com.unciv.models.metadata.GameSettings
-import com.unciv.models.metadata.GameSpeed
 import com.unciv.models.metadata.Player
 import com.unciv.models.ruleset.RulesetCache
 import com.unciv.models.simulation.Simulation
 import com.unciv.models.tilesets.TileSetCache
 import com.unciv.models.metadata.GameSetupInfo
+import com.unciv.models.ruleset.Speed
 import kotlin.time.ExperimentalTime
 
 internal object ConsoleLauncher {
@@ -69,7 +69,7 @@ internal object ConsoleLauncher {
     private fun getGameParameters(civilization1: String, civilization2: String): GameParameters {
         return GameParameters().apply {
             difficulty = "Chieftain"
-            gameSpeed = GameSpeed.Quick
+            speed = Speed.DEFAULT
             noBarbarians = true
             players = ArrayList<Player>().apply {
                 add(Player().apply {
diff --git a/docs/Credits.md b/docs/Credits.md
index 7a229d7817..d0c46ea318 100644
--- a/docs/Credits.md
+++ b/docs/Credits.md
@@ -698,6 +698,50 @@ Unless otherwise specified, all the following are from [the Noun Project](https:
 - [Santa beard vector](https://www.freepik.com/free-vector/positive-santa-ringing-bell-waving-hand_3636285.htm) by katemangostar
 - [Funny christmas vector](https://www.freepik.com/free-vector/snowman-wearing-santa-hat-scarf-mittens_3636292.htm) by katemangostar
 
+- [Circle](https://thenounproject.com/term/circle/1841891/) By Aybige
+- [Arrow](https://thenounproject.com/term/arrow/18123/) By Joe Mortell for movement
+- [Swap](https://thenounproject.com/search/?q=swap&i=1259600) By iconomania for swapping units
+- [Connection](https://thenounproject.com/search/?q=connection&i=1521886) By Travis Avery
+- [Skull](https://thenounproject.com/search/?q=Skull&i=1030702) By Vladimir Belochkin for disbanding units
+- [Crosshair](https://thenounproject.com/search/?q=crosshairs&i=916030) By Bakunetsu Kaito for selecting enemies to attack
+- [City](https://thenounproject.com/search/?q=city&i=571332) By Felix Westphal
+- [Fire](https://thenounproject.com/search/?q=Fire&i=96564) By Lloyd Humphreys for "city being razed" icon
+- [Sleep](https://thenounproject.com/search/?q=sleep&i=1760085) By Saeful Muslim
+- [Banner](https://thenounproject.com/term/banner/866282/) By Emir Palavan for embarked units
+- [Arrow](https://thenounproject.com/term/arrow/18123/) By uzeir syarief for moving between idle units
+- [Replace](https://thenounproject.com/search/?q=replace&i=17858) By Mike Rowe for switching tiles between cities
+- [Resistance](https://thenounproject.com/term/revolution/1315305/) By HeadsOfBirds
+- [Viking Hat](https://thenounproject.com/search/?q=pillage&i=185405) By my name is mud for pillaging improvements
+- [Aim](https://thenounproject.com/search/?q=aim&i=2034920) By Kaviashri for ranged strength
+- [Capitol](https://thenounproject.com/search/?q=capitol&i=160031) By Loren Klein for City-States
+- [Aircraft](https://thenounproject.com/search/?q=aircraft&i=1629000) By Tom Fricker for aircraft icon in city button
+- [radar scan](https://thenounproject.com/search/?q=range&i=1500234) By icon 54 for Range
+- [short range radar](https://thenounproject.com/search/?q=air%20range&i=2612731) by Vectors Point for Intercept range
+- [Puppet](https://thenounproject.com/search/?q=puppet&i=285735) By Ben Davis for puppeted cities
+- [City](https://thenounproject.com/search/?q=city&i=1765370) By Muhajir ila Robbi in the Icon center
+- [Lock](https://thenounproject.com/search/?q=lock&i=3217613) by Vadim Solomakhin for locked tiles
+- [Hourglass](https://thenounproject.com/search/?q=hourglass&i=142268) by I Create Stuff for the 'Turn' icon
+- [Shield](https://thenounproject.com/search/?q=shield&i=813568) by Gregor Cresnar for Religious Strength
+- [skill sword flame](https://thenounproject.com/term/skill-sword-flame/2360212/) by Maxicons) for Remove Heresy
+- [Pencil](https://thenounproject.com/search/?q=pencil&i=4195852) by Muhamad Aldi Maulana for Enter Text Prompt Button / Pencil
+- [Parchment](https://thenounproject.com/term/parchment/1516378/) by hans draiman for Cultured City-States
+- [connection](https://thenounproject.com/term/connection/1365233/) by Popular for Mercantile City-States
+- [crossed sword](https://thenounproject.com/term/crossed-sword/2427559/) by ProSymbols for Militaristic City-States
+- [ship helm](https://thenounproject.com/term/ship-helm/2170591/) by Vectors Market for Maritime City-States
+- [Magnifying Glass](https://thenounproject.com/term/magnifying-glass/1311/) by John Caserta for Mod filter
+- [tick](https://thenounproject.com/term/tick/3968142/) by Adrien Coquet on Nation picker
+- [people](https://thenounproject.com/term/people/458671) by Wilson Joseph as base for Civilopedia category Nations
+- [Mountains ](https://thenounproject.com/term/mountains/15616/) by Andrew J. Young as base for Civilopedia category Terrains
+- [File:Maya.svg](https://en.wikipedia.org/wiki/File:Maya.svg) for Mayan numerals
+- [East side of stela C, Quirigua](https://en.wikipedia.org/wiki/File:East_side_of_stela_C,_Quirigua.PNG) for Mayan calendar symbols
+- [Footprints](https://thenounproject.com/icon/footprints-1393611/) by Abdul Wahhab for movement overlay toggle, slightly modified. Currently unused.
+- Arrows.svg by Intralexical (@will-ca), CC0.
+- [favor](https://thenounproject.com/icon/favor-1029350/) by MICHAEL G BROWN for WLTK marker on City Overview
+- [Party](https://thenounproject.com/icon/party-1784941/) by Adrien Coquet for WLTK header on City Overview
+- [Party](https://thenounproject.com/icon/party-2955155/) by Lars Meiertoberens as additional WLKT decoration
+- [turn right](https://thenounproject.com/icon/turn-right-1920867/) by Alice Design for Resource Overview
+- [Tyrannosaurus Rex](https://thenounproject.com/icon/tyrannosaurus-rex-4130976/) by Amethyst Studio for Civilopedia Eras header
+- [Timer](https://www.flaticon.com/free-icons/timer) created by Gregor Cresnar Premium - Flaticon
 
 ### Main menu
 
diff --git a/docs/Other/Miscellaneous-JSON-files.md b/docs/Other/Miscellaneous-JSON-files.md
index ad84a897f5..661b788f1b 100644
--- a/docs/Other/Miscellaneous-JSON-files.md
+++ b/docs/Other/Miscellaneous-JSON-files.md
@@ -60,6 +60,43 @@ Each era can have the following attributes:
 | settlerBuildings | List of Strings | defaults to none | Buildings that should automatically be built whenever a city is settled when starting a game in this era |
 | startingObsoleteWonders | List of Strings | defaults to none | Wonders (and technically buildings) that should be impossible to built when starting a game in this era. Used in the base game to remove all wonders older than 2 era's |
 
+## Speeds.json
+
+[Link to original](https://github.com/yairm210/Unciv/tree/master/android/assets/jsons/Civ%20V%20-%20Gods%20&%20Kings/Speeds.json)
+
+This file should contain all the speeds you want to use in your mod.
+
+Each speed can have the following attributes:
+
+| Attribute | Type | Optional | Notes |
+| --------- | ---- | -------- | ----- |
+| name | String | required | Name of the speed |
+| modifier | Float (≥0) | defaults to 1.0 | Overall game speed modifier |
+| productionCostModifier | Float (≥0) | defaults to the value of `modifier` | Scales production cost of units and buildings |
+| goldCostModifier | Float (≥0) | defaults to the value of `modifier` | Scales gold costs |
+| scienceCostModifier | Float (≥0) | defaults to the value of `modifier` | Scales science costs |
+| cultureCostModifier | Float (≥0) | defaults to the value of `modifier` | Scales culture costs |
+| faithCostModifier | Float (≥0) | defaults to the value of `modifier` | Scales faith costs |
+| improvementBuildLengthModifier | Float (≥0) | defaults to the value of `modifier` | Scales the time it takes for a worker to build tile improvements |
+| barbarianModifier | Float (≥0) | defaults to the value of `modifier` | Scales the time between barbarian spawns |
+| goldGiftModifier | Float (≥0) | defaults to the value of `modifier` | Scales the influence gained from gifting gold to city-states |
+| cityStateTributeScalingInterval | Float (≥0) | defaults to 6.5 | The number of turns it takes for the amount of gold a player demands from city-states to increase by 5 gold |
+| goldenAgeLengthModifier | Float (≥0) | defaults to the value of `modifier` | Scales the length of golden ages |
+| religiousPressureAdjacentCity | Integer (≥0) | defaults to 6 | Defines how much religious pressure a city exerts on nearby cities |
+| peaceDealDuration | Integer (≥0) | defaults to 10 | The number of turns a peace deal lasts |
+| dealDuration | Integer (≥0) | defaults to 30 | The number of turns a non-peace deal (research agreement, open borders, etc.) lasts |
+| startYear | Float | defaults to -4000 | The start year of the game (negative is BC/BCE) |
+| turns | List of HashMaps | required | The amount of time passed between turns ("yearsPerTurn") and the range of turn numbers ("untilTurn") that this duration applies to |
+
+The below code is an example of a valid "turns" definition and it specifies that the first 50 turns of a game last for 60 years each, then the next 30 turns (and any played after the 80th) last for 40 years each.
+
+```json
+"turns": [
+{"yearsPerTurn": 60, "untilTurn":  50},
+{"yearsPerTurn": 40, "untilTurn":  80}
+]
+```
+
 ## ModOptions.json
 
 <!-- [Link to original](https://github.com/yairm210/Unciv/tree/master/android/assets/jsons/Civ%20V%20-%20Gods%20&%20Kings/ModOptions.json) -->
@@ -185,13 +222,13 @@ Currently the following milestones are supported:
 | --------- | ----------- |
 | Build [building] | Build the building [building] in any city |
 | Anyone build [building] | Anyone must build the building [building] for all players to have this milestone |
-| Add all [comment] in capital | Add all units in the `requiredSpaceshipParts` field of this victory to the capital | 
+| Add all [comment] in capital | Add all units in the `requiredSpaceshipParts` field of this victory to the capital |
 | Destroy all players | You must be the only major civilization with any cities left |
 | Capture all capitals | Capture all the original capitals of major civilizations in the game |
 | Complete [amount] Policy branches | Fully complete at least [amount] policy branches |
 | Win diplomatic vote | At any point in the game win a diplomatic vote (UN). You may lose afterwards and still retain this milestone |
 | Become the world religion | Have your religion be the majority religion in a majority of cities of all major civs |
-| Have highest score after max turns | Basically time victory. Enables the 'max turn' slider and calculates score when that amount is reached |  
+| Have highest score after max turns | Basically time victory. Enables the 'max turn' slider and calculates score when that amount is reached |
 
 
 ## Civilopedia text
diff --git a/tests/src/com/unciv/logic/map/UnitMovementAlgorithmsTests.kt b/tests/src/com/unciv/logic/map/UnitMovementAlgorithmsTests.kt
index dee8d73cab..e430920747 100644
--- a/tests/src/com/unciv/logic/map/UnitMovementAlgorithmsTests.kt
+++ b/tests/src/com/unciv/logic/map/UnitMovementAlgorithmsTests.kt
@@ -7,10 +7,7 @@ import com.unciv.logic.city.CityInfo
 import com.unciv.logic.civilization.CivilizationInfo
 import com.unciv.logic.civilization.diplomacy.DiplomacyManager
 import com.unciv.logic.civilization.diplomacy.DiplomaticStatus
-import com.unciv.models.ruleset.Difficulty
-import com.unciv.models.ruleset.Nation
-import com.unciv.models.ruleset.Ruleset
-import com.unciv.models.ruleset.RulesetCache
+import com.unciv.models.ruleset.*
 import com.unciv.models.ruleset.unit.BaseUnit
 import com.unciv.testing.GdxTestRunner
 import org.junit.Assert
@@ -35,10 +32,11 @@ class UnitMovementAlgorithmsTests {
         civInfo.tech.techsResearched.addAll(ruleSet.technologies.keys)
         civInfo.tech.embarkedUnitsCanEnterOcean = true
         civInfo.tech.unitsCanEmbark = true
-        civInfo.nation = Nation().apply { name = "My nation" }
         civInfo.gameInfo = GameInfo()
         civInfo.gameInfo.ruleSet = ruleSet
         civInfo.gameInfo.difficultyObject = Difficulty()
+        civInfo.gameInfo.speed = ruleSet.speeds[Speed.DEFAULTFORSIMULATION]!!
+        civInfo.nation = Nation().apply { name = "My nation" }
         civInfo.gameInfo.civilizations.add(civInfo)
         unit.civInfo = civInfo
         unit.owner = civInfo.civName
diff --git a/tests/src/com/unciv/uniques/TestGame.kt b/tests/src/com/unciv/uniques/TestGame.kt
index d7dd1e4ce8..ee65013f13 100644
--- a/tests/src/com/unciv/uniques/TestGame.kt
+++ b/tests/src/com/unciv/uniques/TestGame.kt
@@ -39,6 +39,7 @@ class TestGame {
         ruleset = RulesetCache[BaseRuleset.Civ_V_GnK.fullName]!!
         gameInfo.ruleSet = ruleset
         gameInfo.difficultyObject = ruleset.difficulties["Prince"]!!
+        gameInfo.speed = ruleset.speeds[Speed.DEFAULTFORSIMULATION]!!
 
         // Create a tilemap, needed for city centers
         gameInfo.tileMap = TileMap(1, ruleset, false)