diff --git a/build.gradle.kts b/build.gradle.kts
index 77769f836e..79bfa0ee6a 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -45,10 +45,13 @@ allprojects {
     
     apply(plugin = "io.github.yairm210.purity-plugin")
     configure<yairm210.purity.PurityConfiguration>{
-        wellKnownPureFunctions = setOf("kotlin.internal.ir.CHECK_NOT_NULL")
+        wellKnownPureFunctions = setOf()
         wellKnownReadonlyFunctions = setOf(
             "kotlin.collections.any",
-            "kotlin.collections.Iterator.hasNext"
+            "kotlin.collections.all",
+            "kotlin.ranges.coerceAtLeast",
+            // Looks like the Collection.contains is not considered overridden :thunk:
+            "java.util.AbstractCollection.contains",
         )
     }
     
diff --git a/core/src/com/unciv/logic/MultiFilter.kt b/core/src/com/unciv/logic/MultiFilter.kt
index be611f4c1a..7cafca10f3 100644
--- a/core/src/com/unciv/logic/MultiFilter.kt
+++ b/core/src/com/unciv/logic/MultiFilter.kt
@@ -1,5 +1,7 @@
 package com.unciv.logic
 
+import org.jetbrains.annotations.Contract
+
 object MultiFilter {
     private const val andPrefix = "{"
     private const val andSeparator = "} {"
@@ -17,6 +19,7 @@ object MultiFilter {
      *  @param filterFunction The single filter implementation
      *  @param forUniqueValidityTests Inverts the `non-[filter]` test because Unique validity doesn't check for actual matching
      */
+    @Contract("readonly") @Suppress("purity")
     fun multiFilter(
         input: String,
         filterFunction: (String) -> Boolean,
@@ -33,6 +36,7 @@ object MultiFilter {
         return filterFunction(input)
     }
 
+    @Contract("readonly")
     fun getAllSingleFilters(input: String): Sequence<String> = when {
         input.hasSurrounding(andPrefix, andSuffix) && input.contains(andSeparator) ->
             // Resolve "AND" filters
@@ -45,6 +49,7 @@ object MultiFilter {
         else -> sequenceOf(input)
     }
 
+    @Contract("readonly")
     fun String.hasSurrounding(prefix: String, suffix: String) =
         startsWith(prefix) && endsWith(suffix)
 }
diff --git a/core/src/com/unciv/logic/city/City.kt b/core/src/com/unciv/logic/city/City.kt
index 33db1172d1..9185308628 100644
--- a/core/src/com/unciv/logic/city/City.kt
+++ b/core/src/com/unciv/logic/city/City.kt
@@ -28,6 +28,7 @@ import com.unciv.models.stats.GameResource
 import com.unciv.models.stats.INamed
 import com.unciv.models.stats.Stat
 import com.unciv.models.stats.SubStat
+import org.jetbrains.annotations.Contract
 import java.util.UUID
 import kotlin.math.roundToInt
 
@@ -169,6 +170,7 @@ class City : IsPartOfGameInfoSerialization, INamed {
     fun getCenterTileOrNull(): Tile? = if (::centerTile.isInitialized) centerTile else null
     fun getTiles(): Sequence<Tile> = tiles.asSequence().map { tileMap[it] }
     fun getWorkableTiles() = tilesInRange.asSequence().filter { it.getOwner() == civ }
+    @Contract("readonly")
     fun isWorked(tile: Tile) = workedTiles.contains(tile.position)
 
     fun isCapital(): Boolean = cityConstructions.builtBuildingUniqueMap.hasUnique(UniqueType.IndicatesCapital, state)
diff --git a/core/src/com/unciv/logic/map/tile/Tile.kt b/core/src/com/unciv/logic/map/tile/Tile.kt
index 8c0d29f21c..feae190ece 100644
--- a/core/src/com/unciv/logic/map/tile/Tile.kt
+++ b/core/src/com/unciv/logic/map/tile/Tile.kt
@@ -34,6 +34,7 @@ import com.unciv.utils.DebugUtils
 import com.unciv.utils.Log
 import com.unciv.utils.withItem
 import com.unciv.utils.withoutItem
+import org.jetbrains.annotations.Contract
 import kotlin.collections.ArrayList
 import kotlin.collections.HashSet
 import kotlin.math.abs
@@ -257,6 +258,7 @@ class Tile : IsPartOfGameInfoSerialization, Json.Serializable {
         return null
     }
 
+    @Contract("readonly")
     fun getCity(): City? = owningCity
 
     internal fun getNaturalWonder(): Terrain =
@@ -351,6 +353,7 @@ class Tile : IsPartOfGameInfoSerialization, Json.Serializable {
 
     fun getBaseTerrain(): Terrain = baseTerrainObject
 
+    @Contract("readonly")
     fun getOwner(): Civilization? = getCity()?.civ
 
     fun getRoadOwner(): Civilization? {
@@ -401,6 +404,7 @@ class Tile : IsPartOfGameInfoSerialization, Json.Serializable {
         return uniques
     }
 
+    @Contract("readonly")
     fun getWorkingCity(): City? {
         val civInfo = getOwner() ?: return null
         if (owningCity?.isWorked(this) == true) return owningCity // common case
@@ -433,6 +437,7 @@ class Tile : IsPartOfGameInfoSerialization, Json.Serializable {
         return false
     }
 
+    @Contract("readonly")
     fun isWorked(): Boolean = getWorkingCity() != null
     fun providesYield(): Boolean {
         if (getCity() == null) return false
@@ -481,10 +486,12 @@ class Tile : IsPartOfGameInfoSerialization, Json.Serializable {
     }
 
     /** Implements [UniqueParameterType.TileFilter][com.unciv.models.ruleset.unique.UniqueParameterType.TileFilter] */
+    @Contract("readonly")
     fun matchesFilter(filter: String, civInfo: Civilization? = null): Boolean {
         return MultiFilter.multiFilter(filter, { matchesSingleFilter(it, civInfo) })
     }
 
+    @Contract("readonly") @Suppress("purity")
     private fun matchesSingleFilter(filter: String, civInfo: Civilization? = null): Boolean {
         if (matchesSingleTerrainFilter(filter, civInfo)) return true
         if ((improvement == null || improvementIsPillaged) && filter == "unimproved") return true
diff --git a/core/src/com/unciv/models/ruleset/unique/Unique.kt b/core/src/com/unciv/models/ruleset/unique/Unique.kt
index 803d3b0dc7..e90bc195ef 100644
--- a/core/src/com/unciv/models/ruleset/unique/Unique.kt
+++ b/core/src/com/unciv/models/ruleset/unique/Unique.kt
@@ -96,7 +96,7 @@ class Unique(val text: String, val sourceObjectType: UniqueTarget? = null, val s
         return true
     }
 
-    @Contract("readonly") @Suppress("purity")
+    @Contract("readonly")
     private fun getUniqueMultiplier(stateForConditionals: StateForConditionals): Int {
         if (stateForConditionals == StateForConditionals.IgnoreMultiplicationForCaching)
             return 1