if multiple permanents come to battlefield at the same time, they are aware now of each other. (e.g. useful for for Valakut, the Molten Pinnacle).

Mage/src/mage/abilities/AbilityImpl.java

@@ -159,6 +159,8 @@ public abstract class AbilityImpl<T extends AbilityImpl<T>> implements Ability {
                 if (effect.applyEffectsAfter()) {
                     game.applyEffects();
                 }
+                // effects like entersBattlefield have to trigger simultanously so objects see each other
+                game.getState().handleSimultaneousEvent(game);
             }
         }
         return result;

Mage/src/mage/abilities/effects/EffectImpl.java

@@ -118,11 +118,9 @@ public abstract class EffectImpl<T extends Effect<T>> implements Effect<T> {
 
     @Override
     public void setValue(String key, Object value) {
-        if (values == null) {
-            synchronized (this) {
-                if (values == null) {
-                    values = new HashMap<String, Object>();
-                }
+        synchronized (this) {
+            if (values == null) {
+                values = new HashMap<String, Object>();
             }
         }
         values.put(key, value);

Mage/src/mage/game/Game.java

@@ -172,6 +172,12 @@ public interface Game extends MageItem, Serializable {
 
     //game event methods
     void fireEvent(GameEvent event);
+    /**
+     * The events are stored until the resolution of the current effect ends
+     * and fired then all together (e.g. X lands enter the battlefield from Scapeshift)
+     * @param event
+     */
+    void addSimultaneousEvent(GameEvent event);
     boolean replaceEvent(GameEvent event);
 
     //game play methods

Mage/src/mage/game/GameImpl.java

@@ -1790,6 +1790,11 @@ public abstract class GameImpl<T extends GameImpl<T>> implements Game, Serializa
         return state.getPriorityPlayerId();
     }
 
+    @Override
+    public void addSimultaneousEvent(GameEvent event) {
+        state.addSimultaneousEvent(event, this);
+    }
+
     @Override
     public void fireEvent(GameEvent event) {
         state.handleEvent(event, this);

Mage/src/mage/game/GameState.java

@@ -96,6 +96,7 @@ public class GameState implements Serializable, Copyable<GameState> {
     private final Map<UUID, Abilities<ActivatedAbility>> otherAbilities = new HashMap<UUID, Abilities<ActivatedAbility>>();
     private final TurnMods turnMods;
     private final Watchers watchers;
+    
 
     private UUID activePlayerId;
     private UUID priorityPlayerId;
@@ -114,6 +115,7 @@ public class GameState implements Serializable, Copyable<GameState> {
     private Combat combat;
     private Map<String, Object> values = new HashMap<String, Object>();
     private Map<UUID, Zone> zones = new HashMap<UUID, Zone>();
+    private List<GameEvent> simultaneousEvents = new ArrayList<GameEvent>();
 
     public GameState() {
         players = new Players();
@@ -172,6 +174,7 @@ public class GameState implements Serializable, Copyable<GameState> {
             otherAbilities.put(entry.getKey(), entry.getValue().copy());
         }
         this.paused = state.paused;
+        this.simultaneousEvents.addAll(state.simultaneousEvents);
     }
 
     @Override
@@ -482,6 +485,20 @@ public class GameState implements Serializable, Copyable<GameState> {
             Player origPlayer = players.get(copyPlayer.getId());
             origPlayer.restore(copyPlayer);
         }
+        this.simultaneousEvents = state.simultaneousEvents;
+    }
+
+    public void addSimultaneousEvent(GameEvent event, Game game) {
+        simultaneousEvents.add(event);
+    }
+
+    public void handleSimultaneousEvent(Game game) {
+        if (!simultaneousEvents.isEmpty()) {
+            for (GameEvent event:simultaneousEvents) {
+                this.handleEvent(event, game);
+            }
+            simultaneousEvents.clear();
+        }
     }
 
     public void handleEvent(GameEvent event, Game game) {
@@ -665,6 +682,7 @@ public class GameState implements Serializable, Copyable<GameState> {
         watchers.clear();
         values.clear();
         zones.clear();
+        simultaneousEvents.clear();
     }
 
     public void pause() {

Mage/src/mage/game/permanent/PermanentImpl.java

@@ -748,7 +748,11 @@ public abstract class PermanentImpl<T extends PermanentImpl<T>> extends CardImpl
         EntersTheBattlefieldEvent event = new EntersTheBattlefieldEvent(this, sourceId, getControllerId(), fromZone);
         if (!game.replaceEvent(event)) {
             if (fireEvent) {
-                game.fireEvent(event);
+                if (sourceId == null) { // play lands
+                    game.fireEvent(event);
+                } else { // from effects
+                    game.addSimultaneousEvent(event);
+                }
             }
         }
     }