--- a/net/minecraft/world/level/GameRules.java
+++ b/net/minecraft/world/level/GameRules.java
@@ -28,6 +28,10 @@
 import net.minecraft.server.level.EntityPlayer;
 import org.slf4j.Logger;
 
+// CraftBukkit start
+import net.minecraft.server.level.WorldServer;
+// CraftBukkit end
+
 public class GameRules {
 
     public static final int DEFAULT_RANDOM_TICK_SPEED = 3;
@@ -52,7 +56,7 @@
     public static final GameRules.GameRuleKey<GameRules.GameRuleBoolean> RULE_SENDCOMMANDFEEDBACK = register("sendCommandFeedback", GameRules.GameRuleCategory.CHAT, GameRules.GameRuleBoolean.create(true));
     public static final GameRules.GameRuleKey<GameRules.GameRuleBoolean> RULE_REDUCEDDEBUGINFO = register("reducedDebugInfo", GameRules.GameRuleCategory.MISC, GameRules.GameRuleBoolean.create(false, (minecraftserver, gamerules_gameruleboolean) -> {
         int i = gamerules_gameruleboolean.get() ? 22 : 23;
-        Iterator iterator = minecraftserver.getPlayerList().getPlayers().iterator();
+        Iterator iterator = minecraftserver.players().iterator(); // CraftBukkit - per-world
 
         while (iterator.hasNext()) {
             EntityPlayer entityplayer = (EntityPlayer) iterator.next();
@@ -67,7 +71,7 @@
     public static final GameRules.GameRuleKey<GameRules.GameRuleInt> RULE_MAX_ENTITY_CRAMMING = register("maxEntityCramming", GameRules.GameRuleCategory.MOBS, GameRules.GameRuleInt.create(24));
     public static final GameRules.GameRuleKey<GameRules.GameRuleBoolean> RULE_WEATHER_CYCLE = register("doWeatherCycle", GameRules.GameRuleCategory.UPDATES, GameRules.GameRuleBoolean.create(true));
     public static final GameRules.GameRuleKey<GameRules.GameRuleBoolean> RULE_LIMITED_CRAFTING = register("doLimitedCrafting", GameRules.GameRuleCategory.PLAYER, GameRules.GameRuleBoolean.create(false, (minecraftserver, gamerules_gameruleboolean) -> {
-        Iterator iterator = minecraftserver.getPlayerList().getPlayers().iterator();
+        Iterator iterator = minecraftserver.players().iterator(); // CraftBukkit - per-world
 
         while (iterator.hasNext()) {
             EntityPlayer entityplayer = (EntityPlayer) iterator.next();
@@ -83,7 +87,7 @@
     public static final GameRules.GameRuleKey<GameRules.GameRuleBoolean> RULE_DISABLE_RAIDS = register("disableRaids", GameRules.GameRuleCategory.MOBS, GameRules.GameRuleBoolean.create(false));
     public static final GameRules.GameRuleKey<GameRules.GameRuleBoolean> RULE_DOINSOMNIA = register("doInsomnia", GameRules.GameRuleCategory.SPAWNING, GameRules.GameRuleBoolean.create(true));
     public static final GameRules.GameRuleKey<GameRules.GameRuleBoolean> RULE_DO_IMMEDIATE_RESPAWN = register("doImmediateRespawn", GameRules.GameRuleCategory.PLAYER, GameRules.GameRuleBoolean.create(false, (minecraftserver, gamerules_gameruleboolean) -> {
-        Iterator iterator = minecraftserver.getPlayerList().getPlayers().iterator();
+        Iterator iterator = minecraftserver.players().iterator(); // CraftBukkit - per-world
 
         while (iterator.hasNext()) {
             EntityPlayer entityplayer = (EntityPlayer) iterator.next();
@@ -142,7 +146,7 @@
     }
 
     public <T extends GameRules.GameRuleValue<T>> T getRule(GameRules.GameRuleKey<T> gamerules_gamerulekey) {
-        return (GameRules.GameRuleValue) this.rules.get(gamerules_gamerulekey);
+        return (T) this.rules.get(gamerules_gamerulekey); // CraftBukkit - decompile error
     }
 
     public NBTTagCompound createTag() {
@@ -156,7 +160,7 @@
 
     private void loadFromTag(DynamicLike<?> dynamiclike) {
         this.rules.forEach((gamerules_gamerulekey, gamerules_gamerulevalue) -> {
-            Optional optional = dynamiclike.get(gamerules_gamerulekey.id).asString().result();
+            Optional<String> optional = dynamiclike.get(gamerules_gamerulekey.id).asString().result(); // CraftBukkit - decompile error
 
             Objects.requireNonNull(gamerules_gamerulevalue);
             optional.ifPresent(gamerules_gamerulevalue::deserialize);
@@ -176,17 +180,17 @@
     }
 
     private static <T extends GameRules.GameRuleValue<T>> void callVisitorCap(GameRules.GameRuleVisitor gamerules_gamerulevisitor, GameRules.GameRuleKey<?> gamerules_gamerulekey, GameRules.GameRuleDefinition<?> gamerules_gameruledefinition) {
-        gamerules_gamerulevisitor.visit(gamerules_gamerulekey, gamerules_gameruledefinition);
-        gamerules_gameruledefinition.callVisitor(gamerules_gamerulevisitor, gamerules_gamerulekey);
+        gamerules_gamerulevisitor.visit((GameRules.GameRuleKey<T>) gamerules_gamerulekey, (GameRules.GameRuleDefinition<T>) gamerules_gameruledefinition); // CraftBukkit - decompile error
+        ((GameRules.GameRuleDefinition<T>) gamerules_gameruledefinition).callVisitor(gamerules_gamerulevisitor, (GameRules.GameRuleKey<T>) gamerules_gamerulekey); // CraftBukkit - decompile error
     }
 
-    public void assignFrom(GameRules gamerules, @Nullable MinecraftServer minecraftserver) {
+    public void assignFrom(GameRules gamerules, @Nullable WorldServer minecraftserver) { // CraftBukkit - per-world
         gamerules.rules.keySet().forEach((gamerules_gamerulekey) -> {
             this.assignCap(gamerules_gamerulekey, gamerules, minecraftserver);
         });
     }
 
-    private <T extends GameRules.GameRuleValue<T>> void assignCap(GameRules.GameRuleKey<T> gamerules_gamerulekey, GameRules gamerules, @Nullable MinecraftServer minecraftserver) {
+    private <T extends GameRules.GameRuleValue<T>> void assignCap(GameRules.GameRuleKey<T> gamerules_gamerulekey, GameRules gamerules, @Nullable WorldServer minecraftserver) { // CraftBukkit - per-world
         T t0 = gamerules.getRule(gamerules_gamerulekey);
 
         this.getRule(gamerules_gamerulekey).setFrom(t0, minecraftserver);
@@ -254,10 +258,10 @@
 
         private final Supplier<ArgumentType<?>> argument;
         private final Function<GameRules.GameRuleDefinition<T>, T> constructor;
-        final BiConsumer<MinecraftServer, T> callback;
+        final BiConsumer<WorldServer, T> callback; // CraftBukkit - per-world
         private final GameRules.h<T> visitorCaller;
 
-        GameRuleDefinition(Supplier<ArgumentType<?>> supplier, Function<GameRules.GameRuleDefinition<T>, T> function, BiConsumer<MinecraftServer, T> biconsumer, GameRules.h<T> gamerules_h) {
+        GameRuleDefinition(Supplier<ArgumentType<?>> supplier, Function<GameRules.GameRuleDefinition<T>, T> function, BiConsumer<WorldServer, T> biconsumer, GameRules.h<T> gamerules_h) { // CraftBukkit - per-world
             this.argument = supplier;
             this.constructor = function;
             this.callback = biconsumer;
@@ -269,7 +273,7 @@
         }
 
         public T createRule() {
-            return (GameRules.GameRuleValue) this.constructor.apply(this);
+            return this.constructor.apply(this); // CraftBukkit - decompile error
         }
 
         public void callVisitor(GameRules.GameRuleVisitor gamerules_gamerulevisitor, GameRules.GameRuleKey<T> gamerules_gamerulekey) {
@@ -289,17 +293,17 @@
 
         public void setFromArgument(CommandContext<CommandListenerWrapper> commandcontext, String s) {
             this.updateFromArgument(commandcontext, s);
-            this.onChanged(((CommandListenerWrapper) commandcontext.getSource()).getServer());
+            this.onChanged(((CommandListenerWrapper) commandcontext.getSource()).getLevel()); // CraftBukkit - per-world
         }
 
-        public void onChanged(@Nullable MinecraftServer minecraftserver) {
+        public void onChanged(@Nullable WorldServer minecraftserver) { // CraftBukkit - per-world
             if (minecraftserver != null) {
                 this.type.callback.accept(minecraftserver, this.getSelf());
             }
 
         }
 
-        protected abstract void deserialize(String s);
+        public abstract void deserialize(String s); // PAIL - private->public
 
         public abstract String serialize();
 
@@ -313,7 +317,7 @@
 
         protected abstract T copy();
 
-        public abstract void setFrom(T t0, @Nullable MinecraftServer minecraftserver);
+        public abstract void setFrom(T t0, @Nullable WorldServer minecraftserver); // CraftBukkit - per-world
     }
 
     public interface GameRuleVisitor {
@@ -329,7 +333,7 @@
 
         private boolean value;
 
-        static GameRules.GameRuleDefinition<GameRules.GameRuleBoolean> create(boolean flag, BiConsumer<MinecraftServer, GameRules.GameRuleBoolean> biconsumer) {
+        static GameRules.GameRuleDefinition<GameRules.GameRuleBoolean> create(boolean flag, BiConsumer<WorldServer, GameRules.GameRuleBoolean> biconsumer) { // CraftBukkit - per-world
             return new GameRules.GameRuleDefinition<>(BoolArgumentType::bool, (gamerules_gameruledefinition) -> {
                 return new GameRules.GameRuleBoolean(gamerules_gameruledefinition, flag);
             }, biconsumer, GameRules.GameRuleVisitor::visitBoolean);
@@ -354,7 +358,7 @@
             return this.value;
         }
 
-        public void set(boolean flag, @Nullable MinecraftServer minecraftserver) {
+        public void set(boolean flag, @Nullable WorldServer minecraftserver) { // CraftBukkit - per-world
             this.value = flag;
             this.onChanged(minecraftserver);
         }
@@ -365,7 +369,7 @@
         }
 
         @Override
-        protected void deserialize(String s) {
+        public void deserialize(String s) { // PAIL - protected->public
             this.value = Boolean.parseBoolean(s);
         }
 
@@ -384,7 +388,7 @@
             return new GameRules.GameRuleBoolean(this.type, this.value);
         }
 
-        public void setFrom(GameRules.GameRuleBoolean gamerules_gameruleboolean, @Nullable MinecraftServer minecraftserver) {
+        public void setFrom(GameRules.GameRuleBoolean gamerules_gameruleboolean, @Nullable WorldServer minecraftserver) { // CraftBukkit - per-world
             this.value = gamerules_gameruleboolean.value;
             this.onChanged(minecraftserver);
         }
@@ -394,7 +398,7 @@
 
         private int value;
 
-        private static GameRules.GameRuleDefinition<GameRules.GameRuleInt> create(int i, BiConsumer<MinecraftServer, GameRules.GameRuleInt> biconsumer) {
+        private static GameRules.GameRuleDefinition<GameRules.GameRuleInt> create(int i, BiConsumer<WorldServer, GameRules.GameRuleInt> biconsumer) { // CraftBukkit - per-world
             return new GameRules.GameRuleDefinition<>(IntegerArgumentType::integer, (gamerules_gameruledefinition) -> {
                 return new GameRules.GameRuleInt(gamerules_gameruledefinition, i);
             }, biconsumer, GameRules.GameRuleVisitor::visitInteger);
@@ -419,7 +423,7 @@
             return this.value;
         }
 
-        public void set(int i, @Nullable MinecraftServer minecraftserver) {
+        public void set(int i, @Nullable WorldServer minecraftserver) { // CraftBukkit - per-world
             this.value = i;
             this.onChanged(minecraftserver);
         }
@@ -430,7 +434,7 @@
         }
 
         @Override
-        protected void deserialize(String s) {
+        public void deserialize(String s) { // PAIL - protected->public
             this.value = safeParse(s);
         }
 
@@ -470,7 +474,7 @@
             return new GameRules.GameRuleInt(this.type, this.value);
         }
 
-        public void setFrom(GameRules.GameRuleInt gamerules_gameruleint, @Nullable MinecraftServer minecraftserver) {
+        public void setFrom(GameRules.GameRuleInt gamerules_gameruleint, @Nullable WorldServer minecraftserver) { // CraftBukkit - per-world
             this.value = gamerules_gameruleint.value;
             this.onChanged(minecraftserver);
         }