Added "Can only start games from the starting era" conditional, "if [buildingFilter] is not constructed" unique

core/src/com/unciv/logic/civilization/diplomacy/DeclareWar.kt

@@ -26,7 +26,6 @@ object DeclareWar {
     internal fun declareWar(diplomacyManager: DiplomacyManager, declareWarReason: DeclareWarReason) {
         val civInfo = diplomacyManager.civInfo
         val otherCiv = diplomacyManager.otherCiv()
-        if (otherCiv.isDefeated()) throw Exception("Tried to declare war on a defeated civ!")
         val otherCivDiplomacy = diplomacyManager.otherCivDiplomacy()
 
         if (otherCiv.isCityState && declareWarReason.warType == WarType.DirectWar)

core/src/com/unciv/models/ruleset/unique/Conditionals.kt

@@ -171,6 +171,8 @@ object Conditionals {
 
             UniqueType.ConditionalBuildingBuilt ->
                 checkOnCiv { cities.any { it.cityConstructions.containsBuildingOrEquivalent(conditional.params[0]) } }
+            UniqueType.ConditionalBuildingNotBuilt ->
+                checkOnCiv { cities.none { it.cityConstructions.containsBuildingOrEquivalent(conditional.params[0]) } }
             UniqueType.ConditionalBuildingBuiltAll ->
                 checkOnCiv { cities.filter { it.matchesFilter(conditional.params[1]) }.all {
                   it.cityConstructions.containsBuildingOrEquivalent(conditional.params[0]) } }

core/src/com/unciv/models/ruleset/unique/UniqueType.kt

@@ -706,6 +706,7 @@ enum class UniqueType(
     ConditionalAfterGeneratingGreatProphet("after generating a Great Prophet", UniqueTarget.Conditional),
 
     ConditionalBuildingBuilt("if [buildingFilter] is constructed", UniqueTarget.Conditional),
+    ConditionalBuildingNotBuilt("if [buildingFilter] is not constructed", UniqueTarget.Conditional),
     ConditionalBuildingBuiltAll("if [buildingFilter] is constructed in all [cityFilter] cities", UniqueTarget.Conditional),
     ConditionalBuildingBuiltAmount("if [buildingFilter] is constructed in at least [positiveAmount] of [cityFilter] cities", UniqueTarget.Conditional),
     ConditionalBuildingBuiltByAnybody("if [buildingFilter] is constructed by anybody", UniqueTarget.Conditional),
@@ -911,6 +912,7 @@ enum class UniqueType(
     AllowCityStatesSpawnUnits("Allow City States to spawn with additional units", UniqueTarget.ModOptions, flags = UniqueFlag.setOfNoConditionals),
     TradeCivIntroductions("Can trade civilization introductions for [positiveAmount] Gold", UniqueTarget.ModOptions, flags = UniqueFlag.setOfNoConditionals),
     DisableReligion("Disable religion", UniqueTarget.ModOptions, flags = UniqueFlag.setOfNoConditionals),
+    CanOnlyStartFromStartingEra("Can only start games from the starting era", UniqueTarget.ModOptions, flags = UniqueFlag.setOfNoConditionals),
     AllowRazeCapital("Allow raze capital", UniqueTarget.ModOptions, flags = UniqueFlag.setOfNoConditionals),
     AllowRazeHolyCity("Allow raze holy city", UniqueTarget.ModOptions, flags = UniqueFlag.setOfNoConditionals),
 
@@ -1385,6 +1387,6 @@ enum class UniqueType(
         targetTypes.any { uniqueTarget.canAcceptUniqueTarget(it) }
 
     companion object {
-        val uniqueTypeMap: Map<String, UniqueType> = UniqueType.values().associateBy { it.placeholderText }
+        val uniqueTypeMap: Map<String, UniqueType> = entries.associateBy { it.placeholderText }
     }
 }

core/src/com/unciv/ui/screens/newgamescreen/GameOptionsTable.kt

@@ -408,6 +408,10 @@ class GameOptionsTable(
 
     private fun Table.addEraSelectBox() {
         if (ruleset.eras.isEmpty()) return // mod with no techs
+        if (ruleset.modOptions.hasUnique(UniqueType.CanOnlyStartFromStartingEra)){
+            gameParameters.startingEra = ruleset.eras.keys.first()
+            return
+        }
         val eras = ruleset.eras.keys
         addSelectBox("{Starting Era}:", eras, gameParameters.startingEra)
         { gameParameters.startingEra = it; null }

docs/Modders/uniques.md

@@ -2622,6 +2622,9 @@ Simple unique parameters are explained by mouseover. Complex parameters are expl
 ??? example  "Disable religion"
 	Applicable to: ModOptions
 
+??? example  "Can only start games from the default era"
+	Applicable to: ModOptions
+
 ??? example  "Allow raze capital"
 	Applicable to: ModOptions
 
@@ -2842,6 +2845,11 @@ Simple unique parameters are explained by mouseover. Complex parameters are expl
 
 	Applicable to: Conditional
 
+??? example  "<if [buildingFilter] is not constructed>"
+	Example: "<if [Culture] is not constructed>"
+
+	Applicable to: Conditional
+
 ??? example  "<if [buildingFilter] is constructed in all [cityFilter] cities>"
 	Example: "<if [Culture] is constructed in all [in all cities] cities>"