diff --git a/src/main/java/forge/card/abilityfactory/AbilityFactoryChangeZone.java b/src/main/java/forge/card/abilityfactory/AbilityFactoryChangeZone.java
index 2b2617697e7..bc960d18e34 100644
--- a/src/main/java/forge/card/abilityfactory/AbilityFactoryChangeZone.java
+++ b/src/main/java/forge/card/abilityfactory/AbilityFactoryChangeZone.java
@@ -1244,7 +1244,6 @@ public final class AbilityFactoryChangeZone {
 
                     // Does AI need a land?
                     List<Card> hand = ai.getCardsIn(ZoneType.Hand);
-                    System.out.println("Lands in hand = " + CardLists.filter(hand, Presets.LANDS).size() + ", on battlefield = " + CardLists.filter(ai.getCardsIn(ZoneType.Battlefield), Presets.LANDS).size());
                     if (CardLists.filter(hand, Presets.LANDS).size() == 0 && CardLists.filter(ai.getCardsIn(ZoneType.Battlefield), Presets.LANDS).size() < 4) {
                         boolean canCastSomething = false;
                         for (Card cardInHand : hand) {
@@ -1388,7 +1387,7 @@ public final class AbilityFactoryChangeZone {
     private static Card basicManaFixing(final Player ai, final List<Card> list) { // Search for a
                                                                // Basic Land
 
-        final List<Card> combined = ai.getCardsIn(ZoneType.Battlefield);
+        final List<Card> combined = new ArrayList<Card>(ai.getCardsIn(ZoneType.Battlefield));
         combined.addAll(ai.getCardsIn(ZoneType.Hand));
 
         final ArrayList<String> basics = new ArrayList<String>();
@@ -1586,7 +1585,7 @@ public final class AbilityFactoryChangeZone {
         }
         // don't return something to your hand if your hand is full of good stuff
         if (destination.equals(ZoneType.Hand) && origin.equals(ZoneType.Graveyard)) {
-            int handSize = ai.getCardsIn(ZoneType.Hand).size();
+            final int handSize = ai.getCardsIn(ZoneType.Hand).size();
             if (Singletons.getModel().getGame().getPhaseHandler().getPhase().isBefore(PhaseType.MAIN1)) {
                 return false;
             }
@@ -2596,8 +2595,7 @@ public final class AbilityFactoryChangeZone {
         // ex. "Return all blocking/blocked by target creature"
 
         final Player opp = ai.getOpponent();
-        List<Card> humanType = opp.getCardsIn(origin);
-        humanType = AbilityFactory.filterListByType(humanType, params.get("ChangeType"), sa);
+        final List<Card> humanType = AbilityFactory.filterListByType(opp.getCardsIn(origin), params.get("ChangeType"), sa);
         List<Card> computerType = ai.getCardsIn(origin);
         computerType = AbilityFactory.filterListByType(computerType, params.get("ChangeType"), sa);
         final Target tgt = sa.getTarget();
@@ -2762,8 +2760,7 @@ public final class AbilityFactoryChangeZone {
         final ZoneType origin = ZoneType.smartValueOf(params.get("Origin"));
 
         final Player opp = ai.getOpponent();
-        List<Card> humanType = opp.getCardsIn(origin);
-        humanType = AbilityFactory.filterListByType(humanType, params.get("ChangeType"), sa);
+        final List<Card> humanType = AbilityFactory.filterListByType(opp.getCardsIn(origin), params.get("ChangeType"), sa);
         List<Card> computerType = ai.getCardsIn(origin);
         computerType = AbilityFactory.filterListByType(computerType, params.get("ChangeType"), sa);
 
diff --git a/src/main/java/forge/card/abilityfactory/AbilityFactoryDealDamage.java b/src/main/java/forge/card/abilityfactory/AbilityFactoryDealDamage.java
index 9ba635ff0dc..89d0a58e100 100644
--- a/src/main/java/forge/card/abilityfactory/AbilityFactoryDealDamage.java
+++ b/src/main/java/forge/card/abilityfactory/AbilityFactoryDealDamage.java
@@ -527,8 +527,7 @@ public class AbilityFactoryDealDamage {
         final Target tgt = saMe.getTarget();
         final Card source = saMe.getSourceCard();
         final HashMap<String, String> params = this.abilityFactory.getMapParams();
-        List<Card> hPlay = pl.getCardsIn(ZoneType.Battlefield);
-        hPlay = CardLists.getValidCards(hPlay, tgt.getValidTgts(), ai, source);
+        List<Card> hPlay = CardLists.getValidCards(pl.getCardsIn(ZoneType.Battlefield), tgt.getValidTgts(), ai, source);
 
         final ArrayList<Object> objects = tgt.getTargets();
         if (params.containsKey("TargetUnique")) {
@@ -1254,8 +1253,8 @@ public class AbilityFactoryDealDamage {
         }
 
         // TODO: X may be something different than X paid
-        List<Card> list = player.getCardsIn(ZoneType.Battlefield);
-        list = CardLists.getValidCards(list, validC.split(","), source.getController(), source);
+        List<Card> list = 
+                CardLists.getValidCards(player.getCardsIn(ZoneType.Battlefield), validC.split(","), source.getController(), source);
 
         final Predicate<Card> filterKillable = new Predicate<Card>() {
             @Override
diff --git a/src/main/java/forge/card/abilityfactory/AbilityFactoryDebuff.java b/src/main/java/forge/card/abilityfactory/AbilityFactoryDebuff.java
index a5f65834200..b854b5b2f86 100644
--- a/src/main/java/forge/card/abilityfactory/AbilityFactoryDebuff.java
+++ b/src/main/java/forge/card/abilityfactory/AbilityFactoryDebuff.java
@@ -811,10 +811,8 @@ public final class AbilityFactoryDebuff {
             valid = params.get("ValidCards");
         }
 
-        List<Card> comp = ai.getCardsIn(ZoneType.Battlefield);
-        comp = CardLists.getValidCards(comp, valid, hostCard.getController(), hostCard);
-        List<Card> human = opp.getCardsIn(ZoneType.Battlefield);
-        human = CardLists.getValidCards(human, valid, hostCard.getController(), hostCard);
+        List<Card> comp = CardLists.getValidCards(ai.getCardsIn(ZoneType.Battlefield), valid, hostCard.getController(), hostCard);
+        List<Card> human = CardLists.getValidCards(opp.getCardsIn(ZoneType.Battlefield), valid, hostCard.getController(), hostCard);
 
         // TODO - add blocking situations here also
 
diff --git a/src/main/java/forge/card/abilityfactory/AbilityFactoryDestroy.java b/src/main/java/forge/card/abilityfactory/AbilityFactoryDestroy.java
index 24f25b7f347..3e170feb23f 100644
--- a/src/main/java/forge/card/abilityfactory/AbilityFactoryDestroy.java
+++ b/src/main/java/forge/card/abilityfactory/AbilityFactoryDestroy.java
@@ -246,8 +246,7 @@ public class AbilityFactoryDestroy {
         // Targeting
         if (abTgt != null) {
             abTgt.resetTargets();
-            list = ai.getOpponent().getCardsIn(ZoneType.Battlefield);
-            list = CardLists.getTargetableCards(list, sa);
+            list = CardLists.getTargetableCards(ai.getOpponent().getCardsIn(ZoneType.Battlefield), sa);
             list = CardLists.getValidCards(list, abTgt.getValidTgts(), source.getController(), source);
             if (params.containsKey("AITgts")) {
                 list = CardLists.getValidCards(list, params.get("AITgts"), sa.getActivatingPlayer(), source);
@@ -846,21 +845,22 @@ public class AbilityFactoryDestroy {
         final HashMap<String, String> params = af.getMapParams();
         final Target tgt = sa.getTarget();
         String valid = "";
+        if (mandatory) {
+            return true;
+        }
         if (params.containsKey("ValidCards")) {
             valid = params.get("ValidCards");
         }
-        List<Card> humanlist = ai.getOpponent().getCardsIn(ZoneType.Battlefield);
-        List<Card> computerlist = ai.getCardsIn(ZoneType.Battlefield);
+        List<Card> humanlist = 
+                CardLists.getValidCards(ai.getOpponent().getCardsIn(ZoneType.Battlefield), valid.split(","), source.getController(), source);
+        List<Card> computerlist = 
+                CardLists.getValidCards(ai.getCardsIn(ZoneType.Battlefield), valid.split(","), source.getController(), source);
         if (sa.getTarget() != null) {
             tgt.resetTargets();
             sa.getTarget().addTarget(ai.getOpponent());
             computerlist.clear();
         }
-        if (mandatory) {
-            return true;
-        }
-        humanlist = CardLists.getValidCards(humanlist, valid.split(","), source.getController(), source);
-        computerlist = CardLists.getValidCards(computerlist, valid.split(","), source.getController(), source);
+
         humanlist = CardLists.filter(humanlist, new Predicate<Card>() {
             @Override
             public boolean apply(final Card c) {
@@ -930,20 +930,18 @@ public class AbilityFactoryDestroy {
             valid = valid.replace("X", Integer.toString(xPay));
         }
 
-        List<Card> humanlist = ai.getOpponent().getCardsIn(ZoneType.Battlefield);
-        List<Card> computerlist = ai.getCardsIn(ZoneType.Battlefield);
-
         final Target tgt = sa.getTarget();
 
+        List<Card> humanlist = 
+                CardLists.getValidCards(ai.getOpponent().getCardsIn(ZoneType.Battlefield), valid.split(","), source.getController(), source);
+        List<Card> computerlist = 
+                CardLists.getValidCards(ai.getCardsIn(ZoneType.Battlefield), valid.split(","), source.getController(), source);
         if (sa.getTarget() != null) {
             tgt.resetTargets();
             sa.getTarget().addTarget(ai.getOpponent());
             computerlist.clear();
         }
 
-        humanlist = CardLists.getValidCards(humanlist, valid.split(","), source.getController(), source);
-        computerlist = CardLists.getValidCards(computerlist, valid.split(","), source.getController(), source);
-
         humanlist = CardLists.filter(humanlist, new Predicate<Card>() {
             @Override
             public boolean apply(final Card c) {
diff --git a/src/main/java/forge/card/abilityfactory/AbilityFactoryGainControl.java b/src/main/java/forge/card/abilityfactory/AbilityFactoryGainControl.java
index a617ea2285e..6c2609c602c 100644
--- a/src/main/java/forge/card/abilityfactory/AbilityFactoryGainControl.java
+++ b/src/main/java/forge/card/abilityfactory/AbilityFactoryGainControl.java
@@ -334,8 +334,8 @@ public class AbilityFactoryGainControl {
             }
         }
 
-        List<Card> list = opp.getCardsIn(ZoneType.Battlefield);
-        list = CardLists.getValidCards(list, tgt.getValidTgts(), sa.getSourceCard().getController(), sa.getSourceCard());
+        List<Card> list = 
+                CardLists.getValidCards(opp.getCardsIn(ZoneType.Battlefield), tgt.getValidTgts(), sa.getActivatingPlayer(), sa.getSourceCard());
         // AI won't try to grab cards that are filtered out of AI decks on
         // purpose
         list = CardLists.filter(list, new Predicate<Card>() {
@@ -854,8 +854,8 @@ public class AbilityFactoryGainControl {
         final Target tgt = sa.getTarget();
         tgt.resetTargets();
 
-        List<Card> list = ai.getOpponent().getCardsIn(ZoneType.Battlefield);
-        list = CardLists.getValidCards(list, tgt.getValidTgts(), ai, sa.getSourceCard());
+        List<Card> list = 
+                CardLists.getValidCards(ai.getOpponent().getCardsIn(ZoneType.Battlefield), tgt.getValidTgts(), ai, sa.getSourceCard());
         // AI won't try to grab cards that are filtered out of AI decks on
         // purpose
         list = CardLists.filter(list, new Predicate<Card>() {
diff --git a/src/main/java/forge/card/abilityfactory/AbilityFactoryZoneAffecting.java b/src/main/java/forge/card/abilityfactory/AbilityFactoryZoneAffecting.java
index 708f3623ddd..a4d6cecf7bd 100644
--- a/src/main/java/forge/card/abilityfactory/AbilityFactoryZoneAffecting.java
+++ b/src/main/java/forge/card/abilityfactory/AbilityFactoryZoneAffecting.java
@@ -1328,8 +1328,8 @@ public class AbilityFactoryZoneAffecting {
                 }
 
                 if (mode.equals("NotRemembered")) {
-                    List<Card> dPHand = p.getCardsIn(ZoneType.Hand);
-                    dPHand = CardLists.getValidCards(dPHand, "Card.IsNotRemembered", source.getController(), source);
+                    final List<Card> dPHand = 
+                            CardLists.getValidCards(p.getCardsIn(ZoneType.Hand), "Card.IsNotRemembered", source.getController(), source);
                     for (final Card c : dPHand) {
                         p.discard(c, sa);
                         discarded.add(c);
@@ -1395,7 +1395,7 @@ public class AbilityFactoryZoneAffecting {
                 } else if (mode.equals("RevealYouChoose") || mode.equals("RevealOppChoose") || mode.equals("TgtChoose")) {
                     // Is Reveal you choose right? I think the wrong player is
                     // being used?
-                    List<Card> dPHand = p.getCardsIn(ZoneType.Hand);
+                    List<Card> dPHand = new ArrayList<Card>(p.getCardsIn(ZoneType.Hand));
                     if (dPHand.size() != 0) {
                         if (params.containsKey("RevealNumber")) {
                             String amountString = params.get("RevealNumber");
@@ -1717,7 +1717,7 @@ public class AbilityFactoryZoneAffecting {
     private static boolean discardTargetAI(final Player ai, final AbilityFactory af, final SpellAbility sa) {
         final Target tgt = sa.getTarget();
         Player opp = ai.getOpponent();
-        if (opp.getCardsIn(ZoneType.Hand).size() < 1) {
+        if (opp.getCardsIn(ZoneType.Hand).isEmpty()) {
             return false;
         }
         if (tgt != null) {
diff --git a/src/main/java/forge/card/cardfactory/CardFactoryCreatures.java b/src/main/java/forge/card/cardfactory/CardFactoryCreatures.java
index 5360a777cd1..ff56950d4a4 100644
--- a/src/main/java/forge/card/cardfactory/CardFactoryCreatures.java
+++ b/src/main/java/forge/card/cardfactory/CardFactoryCreatures.java
@@ -118,7 +118,7 @@ public class CardFactoryCreatures {
 
             @Override
             public boolean canPlayAI() {
-                List<Card> perms = getActivatingPlayer().getCardsIn(ZoneType.Battlefield);
+                List<Card> perms = new ArrayList<Card>(getActivatingPlayer().getCardsIn(ZoneType.Battlefield));
                 perms = CardLists.filter(CardLists.getTargetableCards(perms, this), new Predicate<Card>() {
                     @Override
                     public boolean apply(final Card c) {
@@ -155,7 +155,8 @@ public class CardFactoryCreatures {
             @Override
             public void execute() {
 
-                final List<Card> artifacts = CardLists.filter(card.getController().getCardsIn(ZoneType.Battlefield), CardPredicates.Presets.ARTIFACTS);
+                final List<Card> artifacts = 
+                        CardLists.filter(card.getController().getCardsIn(ZoneType.Battlefield), CardPredicates.Presets.ARTIFACTS);
                 if (card.getController().isHuman()) {
                     
 
@@ -419,7 +420,7 @@ public class CardFactoryCreatures {
                     return false;
                 }
 
-                List<Card> targetables = getActivatingPlayer().getOpponent().getCardsIn(ZoneType.Battlefield);
+                List<Card> targetables = new ArrayList<Card>(getActivatingPlayer().getOpponent().getCardsIn(ZoneType.Battlefield));
 
                 targetables = CardLists.filter(CardLists.getTargetableCards(targetables, this), new Predicate<Card>() {
                     @Override
@@ -587,15 +588,15 @@ public class CardFactoryCreatures {
             } // resolve()
 
             public int countKithkin() {
-                List<Card> kithkin = card.getController().getCardsIn(ZoneType.Battlefield);
-                kithkin = CardLists.filter(kithkin, new Predicate<Card>() {
+                final List<Card> kithkin = 
+                        CardLists.filter(card.getController().getCardsIn(ZoneType.Battlefield), new Predicate<Card>() {
 
-                    @Override
-                    public boolean apply(final Card c) {
-                        return (c.isType("Kithkin")) && !c.equals(card);
-                    }
-
-                });
+                        @Override
+                        public boolean apply(final Card c) {
+                            return (c.isType("Kithkin")) && !c.equals(card);
+                        }
+    
+                    });
                 return kithkin.size();
 
             }
@@ -713,7 +714,7 @@ public class CardFactoryCreatures {
                 }
 
                 // Get rid of Planeswalkers:
-                list = ai.getOpponent().getCardsIn(ZoneType.Battlefield);
+                list = new ArrayList<Card>(ai.getOpponent().getCardsIn(ZoneType.Battlefield));
                 list = CardLists.filter(list, new Predicate<Card>() {
                     @Override
                     public boolean apply(final Card crd) {
@@ -757,8 +758,8 @@ public class CardFactoryCreatures {
                 int intermSumPower = 0;
                 int intermSumToughness = 0;
                 // intermSumPower = intermSumToughness = 0;
-                List<Card> creats = card.getController().getCardsIn(ZoneType.Graveyard);
-                creats = CardLists.filter(creats, new Predicate<Card>() {
+                List<Card> creats = 
+                        CardLists.filter(card.getController().getCardsIn(ZoneType.Graveyard), new Predicate<Card>() {
                     @Override
                     public boolean apply(final Card c) {
                         return c.isCreature() && !c.equals(card);
diff --git a/src/main/java/forge/card/cardfactory/CardFactoryInstants.java b/src/main/java/forge/card/cardfactory/CardFactoryInstants.java
index 4ab0be3a196..f153a935aac 100644
--- a/src/main/java/forge/card/cardfactory/CardFactoryInstants.java
+++ b/src/main/java/forge/card/cardfactory/CardFactoryInstants.java
@@ -164,7 +164,7 @@ public class CardFactoryInstants {
                 }
 
                 public void computerResolve() {
-                    final List<Card> list = card.getController().getCardsIn(ZoneType.Library);
+                    final List<Card> list = new ArrayList<Card>(card.getController().getCardsIn(ZoneType.Library));
                     final List<Card> selectedCards = new ArrayList<Card>();
 
                     // pick best creature
diff --git a/src/main/java/forge/card/cardfactory/CardFactoryLands.java b/src/main/java/forge/card/cardfactory/CardFactoryLands.java
index 0c5a6b0e47f..900a2c73d3d 100644
--- a/src/main/java/forge/card/cardfactory/CardFactoryLands.java
+++ b/src/main/java/forge/card/cardfactory/CardFactoryLands.java
@@ -279,8 +279,7 @@ class CardFactoryLands {
                 }
 
                 public void computerExecute() {
-                    List<Card> hand = card.getController().getCardsIn(ZoneType.Hand);
-                    hand = CardLists.getType(hand, type);
+                    List<Card> hand = CardLists.getType(card.getController().getCardsIn(ZoneType.Hand), type);
                     if (hand.size() > 0) {
                         this.revealCard(hand.get(0));
                     } else {
diff --git a/src/main/java/forge/card/cardfactory/CardFactoryUtil.java b/src/main/java/forge/card/cardfactory/CardFactoryUtil.java
index 1074531e5cb..2ac96cf3cb8 100644
--- a/src/main/java/forge/card/cardfactory/CardFactoryUtil.java
+++ b/src/main/java/forge/card/cardfactory/CardFactoryUtil.java
@@ -4732,8 +4732,8 @@ public class CardFactoryUtil {
                     public void execute() {
                         // Target as Modular is Destroyed
                         if (card.getController().isComputer()) {
-                            List<Card> choices = card.getController().getCardsIn(ZoneType.Battlefield);
-                            choices = CardLists.filter(choices, new Predicate<Card>() {
+                            List<Card> choices = 
+                                    CardLists.filter(card.getController().getCardsIn(ZoneType.Battlefield), new Predicate<Card>() {
                                 @Override
                                 public boolean apply(final Card c) {
                                     return c.isCreature() && c.isArtifact();
diff --git a/src/main/java/forge/card/cost/CostExile.java b/src/main/java/forge/card/cost/CostExile.java
index 439de279ef5..bc62c77dcf9 100644
--- a/src/main/java/forge/card/cost/CostExile.java
+++ b/src/main/java/forge/card/cost/CostExile.java
@@ -157,7 +157,7 @@ public class CostExile extends CostPartWithList {
                 typeList.add(Singletons.getModel().getGame().getStack().peekAbility(i).getSourceCard());
             }
         } else {
-            typeList = activator.getCardsIn(this.getFrom());
+            typeList = new ArrayList<Card>(activator.getCardsIn(this.getFrom()));
         }
         if (!this.getThis()) {
             typeList = CardLists.getValidCards(typeList, this.getType().split(";"), activator, source);
diff --git a/src/main/java/forge/card/cost/CostPutCounter.java b/src/main/java/forge/card/cost/CostPutCounter.java
index b10ab5b0c89..185fc367996 100644
--- a/src/main/java/forge/card/cost/CostPutCounter.java
+++ b/src/main/java/forge/card/cost/CostPutCounter.java
@@ -217,7 +217,8 @@ public class CostPutCounter extends CostPartWithList {
                 c = AbilityFactory.calculateAmount(source, this.getAmount(), ability);
             }
 
-            final List<Card> typeList = CardLists.getValidCards(ai.getCardsIn(ZoneType.Battlefield), this.getType().split(";"), ai, source);
+            final List<Card> typeList = 
+                    CardLists.getValidCards(ai.getCardsIn(ZoneType.Battlefield), this.getType().split(";"), ai, source);
 
             Card card = null;
             if (this.getType().equals("Creature.YouCtrl")) {
diff --git a/src/main/java/forge/card/cost/CostRemoveCounter.java b/src/main/java/forge/card/cost/CostRemoveCounter.java
index cb6caaa2be6..88d73cf88f7 100644
--- a/src/main/java/forge/card/cost/CostRemoveCounter.java
+++ b/src/main/java/forge/card/cost/CostRemoveCounter.java
@@ -289,7 +289,8 @@ public class CostRemoveCounter extends CostPartWithList {
 
         if (!this.getThis()) {
             this.getList().clear();
-            final List<Card> typeList = CardLists.getValidCards(ai.getCardsIn(this.getZone()), this.getType().split(";"), ai, source);
+            final List<Card> typeList = 
+                    CardLists.getValidCards(ai.getCardsIn(this.getZone()), this.getType().split(";"), ai, source);
             for (Card card : typeList) {
                 if (card.getCounters(this.getCounter()) >= c) {
                     this.addToList(card);
diff --git a/src/main/java/forge/card/cost/CostReveal.java b/src/main/java/forge/card/cost/CostReveal.java
index ba4fa496fd4..3ed3972b6ac 100644
--- a/src/main/java/forge/card/cost/CostReveal.java
+++ b/src/main/java/forge/card/cost/CostReveal.java
@@ -64,7 +64,7 @@ public class CostReveal extends CostPartWithList {
      */
     @Override
     public final boolean canPay(final SpellAbility ability, final Card source, final Player activator, final Cost cost) {
-        List<Card> handList = activator.getCardsIn(ZoneType.Hand);
+        List<Card> handList = new ArrayList<Card>(activator.getCardsIn(ZoneType.Hand));
         final String type = this.getType();
         final Integer amount = this.convertAmount();
 
@@ -109,7 +109,7 @@ public class CostReveal extends CostPartWithList {
 
             this.getList().add(source);
         } else if (this.getType().equals("Hand")) {
-            this.setList(ai.getCardsIn(ZoneType.Hand));
+            this.setList(new ArrayList<Card>(ai.getCardsIn(ZoneType.Hand)));
             return true;
         } else {
             hand = CardLists.getValidCards(hand, type.split(";"), ai, source);
diff --git a/src/main/java/forge/card/cost/CostTapType.java b/src/main/java/forge/card/cost/CostTapType.java
index f3c43b28e0e..6d455ca6af9 100644
--- a/src/main/java/forge/card/cost/CostTapType.java
+++ b/src/main/java/forge/card/cost/CostTapType.java
@@ -191,8 +191,8 @@ public class CostTapType extends CostPartWithList {
         if (c == null) {
             final String sVar = ability.getSVar(amount);
             if (sVar.equals("XChoice")) {
-                List<Card> typeList = ai.getCardsIn(ZoneType.Battlefield);
-                typeList = CardLists.getValidCards(typeList, this.getType().split(";"), ability.getActivatingPlayer(), ability.getSourceCard());
+                List<Card> typeList = 
+                        CardLists.getValidCards(ai.getCardsIn(ZoneType.Battlefield), this.getType().split(";"), ability.getActivatingPlayer(), ability.getSourceCard());
                 typeList = CardLists.filter(typeList, Presets.UNTAPPED);
                 c = typeList.size();
                 source.setSVar("ChosenX", "Number$" + Integer.toString(c));
diff --git a/src/main/java/forge/card/cost/CostUtil.java b/src/main/java/forge/card/cost/CostUtil.java
index d184b8e9813..c1e8a9eff2a 100644
--- a/src/main/java/forge/card/cost/CostUtil.java
+++ b/src/main/java/forge/card/cost/CostUtil.java
@@ -83,8 +83,8 @@ public class CostUtil {
                     continue;
                 }
 
-                List<Card> typeList = ai.getCardsIn(ZoneType.Battlefield);
-                typeList = CardLists.getValidCards(typeList, type.split(","), source.getController(), source);
+                final List<Card> typeList = 
+                        CardLists.getValidCards(ai.getCardsIn(ZoneType.Battlefield), type.split(","), source.getController(), source);
                 if (ComputerUtil.getCardPreference(ai, source, "SacCost", typeList) == null) {
                     return false;
                 }
@@ -118,8 +118,7 @@ public class CostUtil {
                     continue;
                 }
 
-                List<Card> typeList = ai.getCardsIn(ZoneType.Battlefield);
-                typeList = CardLists.getValidCards(typeList, type.split(","), source.getController(), source);
+                final List<Card> typeList = CardLists.getValidCards(ai.getCardsIn(ZoneType.Battlefield), type.split(","), source.getController(), source);
                 if (ComputerUtil.getCardPreference(ai, source, "SacCost", typeList) == null) {
                     return false;
                 }
@@ -212,11 +211,10 @@ public class CostUtil {
                 final CostDiscard disc = (CostDiscard) part;
 
                 final String type = disc.getType();
-                List<Card> typeList = ai.getCardsIn(ZoneType.Hand);
+                final List<Card> typeList = CardLists.getValidCards(ai.getCardsIn(ZoneType.Hand), type.split(","), source.getController(), source);
                 if (typeList.size() > ai.getMaxHandSize()) {
                     continue;
                 }
-                typeList = CardLists.getValidCards(typeList, type.split(","), source.getController(), source);
                 if (ComputerUtil.getCardPreference(ai, source, "DiscardCost", typeList) == null) {
                     return false;
                 }
diff --git a/src/main/java/forge/game/phase/Combat.java b/src/main/java/forge/game/phase/Combat.java
index 2bcd838e739..d30cd208748 100644
--- a/src/main/java/forge/game/phase/Combat.java
+++ b/src/main/java/forge/game/phase/Combat.java
@@ -120,8 +120,8 @@ public class Combat {
     private void fillDefenderMaps(final Player defender) {
         this.defenders.add(defender);
         this.defenderMap.put(defender, new ArrayList<Card>());
-        List<Card> planeswalkers = defender.getCardsIn(ZoneType.Battlefield);
-        planeswalkers = CardLists.filter(planeswalkers, CardPredicates.Presets.PLANEWALKERS);
+        List<Card> planeswalkers = 
+                CardLists.filter(defender.getCardsIn(ZoneType.Battlefield), CardPredicates.Presets.PLANEWALKERS);
         for (final Card pw : planeswalkers) {
             this.defenders.add(pw);
             this.defenderMap.put(pw, new ArrayList<Card>());
diff --git a/src/main/java/forge/game/phase/EndOfTurn.java b/src/main/java/forge/game/phase/EndOfTurn.java
index ab7d1096877..f0e610932e3 100644
--- a/src/main/java/forge/game/phase/EndOfTurn.java
+++ b/src/main/java/forge/game/phase/EndOfTurn.java
@@ -229,7 +229,7 @@ public class EndOfTurn extends Phase implements java.io.Serializable {
     private static void endOfTurnLighthouseChronologist() {
         final Player player = Singletons.getModel().getGame().getPhaseHandler().getPlayerTurn();
         final Player opponent = player.getOpponent();
-        List<Card> list = opponent.getCardsIn(ZoneType.Battlefield);
+        List<Card> list = new ArrayList<Card>(opponent.getCardsIn(ZoneType.Battlefield));
 
         list = CardLists.filter(list, new Predicate<Card>() {
             @Override
diff --git a/src/main/java/forge/game/phase/Untap.java b/src/main/java/forge/game/phase/Untap.java
index 84ace75d6a3..374da0612da 100644
--- a/src/main/java/forge/game/phase/Untap.java
+++ b/src/main/java/forge/game/phase/Untap.java
@@ -111,7 +111,7 @@ public class Untap extends Phase implements java.io.Serializable {
         final Player player = Singletons.getModel().getGame().getPhaseHandler().getPlayerTurn();
         final Predicate<Card> tappedCanUntap = Predicates.and(Presets.TAPPED, Presets.CANUNTAP);
                 
-        List<Card> list = player.getCardsIn(ZoneType.Battlefield);
+        List<Card> list = new ArrayList<Card>(player.getCardsIn(ZoneType.Battlefield));
 
         for (final Card c : list) {
             if (c.getBounceAtUntap() && c.getName().contains("Undiscovered Paradise")) {
@@ -185,7 +185,7 @@ public class Untap extends Phase implements java.io.Serializable {
         }
 
         // opponent untapping during your untap phase
-        final List<Card> opp = player.getOpponent().getCardsIn(ZoneType.Battlefield);
+        final List<Card> opp = new ArrayList<Card>(player.getOpponent().getCardsIn(ZoneType.Battlefield));
         for (final Card oppCard : opp) {
             if (oppCard.hasKeyword("CARDNAME untaps during each other player's untap step.")) {
                 oppCard.untap();
@@ -235,7 +235,7 @@ public class Untap extends Phase implements java.io.Serializable {
         if (Singletons.getModel().getGame().isCardInPlay("Damping Field") || Singletons.getModel().getGame().isCardInPlay("Imi Statue")) {
             final Player turnOwner = Singletons.getModel().getGame().getPhaseHandler().getPlayerTurn(); 
             if (turnOwner.isComputer()) {
-                List<Card> artList = turnOwner.getCardsIn(ZoneType.Battlefield);
+                List<Card> artList = new ArrayList<Card>(turnOwner.getCardsIn(ZoneType.Battlefield));
                 artList = CardLists.filter(artList, Presets.ARTIFACTS);
                 artList = CardLists.filter(artList, tappedCanUntap);
                 if (artList.size() > 0) {
@@ -265,7 +265,7 @@ public class Untap extends Phase implements java.io.Serializable {
                         }
                     } // selectCard()
                 }; // Input
-                List<Card> artList = turnOwner.getCardsIn(ZoneType.Battlefield);
+                List<Card> artList = new ArrayList<Card>(turnOwner.getCardsIn(ZoneType.Battlefield));
                 artList = CardLists.filter(artList, Presets.ARTIFACTS);
                 artList = CardLists.filter(artList, tappedCanUntap);
                 if (artList.size() > 0) {
@@ -304,8 +304,7 @@ public class Untap extends Phase implements java.io.Serializable {
                         }
                     } // selectCard()
                 }; // Input
-                List<Card> creatures = player.getCreaturesInPlay();
-                creatures = CardLists.filter(creatures, tappedCanUntap);
+                final List<Card> creatures = CardLists.filter(player.getCreaturesInPlay(), tappedCanUntap);
                 if (creatures.size() > 0) {
                     Singletons.getModel().getMatch().getInput().setInput(target);
                 }
diff --git a/src/main/java/forge/game/player/ComputerUtil.java b/src/main/java/forge/game/player/ComputerUtil.java
index 31fb78ae4fa..226d517a3ca 100644
--- a/src/main/java/forge/game/player/ComputerUtil.java
+++ b/src/main/java/forge/game/player/ComputerUtil.java
@@ -1460,8 +1460,8 @@ public class ComputerUtil {
      */
     public static List<Card> chooseSacrificeType(final Player ai, final String type, final Card activate, final Card target,
             final int amount) {
-        List<Card> typeList = ai.getCardsIn(ZoneType.Battlefield);
-        typeList = CardLists.getValidCards(typeList, type.split(";"), activate.getController(), activate);
+        List<Card> typeList = 
+                CardLists.getValidCards(ai.getCardsIn(ZoneType.Battlefield), type.split(";"), activate.getController(), activate);
         if (ai.hasKeyword("You can't sacrifice creatures to cast spells or activate abilities.")) {
             typeList = CardLists.getNotType(typeList, "Creature");
         }
@@ -1559,7 +1559,7 @@ public class ComputerUtil {
             if (hand.size() <= 0) {
                 continue;
             }
-            List<Card> aiCards = ai.getCardsIn(ZoneType.Battlefield);
+            final List<Card> aiCards = ai.getCardsIn(ZoneType.Battlefield);
             final int numLandsInPlay = Iterables.size(Iterables.filter(aiCards, CardPredicates.Presets.LANDS));
             final List<Card> landsInHand = CardLists.filter(hand, CardPredicates.Presets.LANDS);
             final int numLandsInHand = landsInHand.size();
@@ -1619,8 +1619,7 @@ public class ComputerUtil {
                 typeList = CardLists.getValidCards(typeList, type.split(","), activate.getController(), activate);
             }
         } else {
-            typeList = ai.getCardsIn(zone);
-            typeList = CardLists.getValidCards(typeList, type.split(","), activate.getController(), activate);
+            typeList = CardLists.getValidCards(ai.getCardsIn(zone), type.split(","), activate.getController(), activate);
         }
         if ((target != null) && target.getController().isComputer() && typeList.contains(target)) {
             typeList.remove(target); // don't exile the card we're pumping
@@ -1655,8 +1654,8 @@ public class ComputerUtil {
      * @return a {@link forge.CardList} object.
      */
     public static List<Card> chooseTapType(final Player ai, final String type, final Card activate, final boolean tap, final int amount) {
-        List<Card> typeList = ai.getCardsIn(ZoneType.Battlefield);
-        typeList = CardLists.getValidCards(typeList, type.split(","), activate.getController(), activate);
+        List<Card> typeList = 
+                CardLists.getValidCards(ai.getCardsIn(ZoneType.Battlefield), type.split(","), activate.getController(), activate);
 
         // is this needed?
         typeList = CardLists.filter(typeList, Presets.UNTAPPED);
@@ -1695,8 +1694,8 @@ public class ComputerUtil {
      * @return a {@link forge.CardList} object.
      */
     public static List<Card> chooseUntapType(final Player ai, final String type, final Card activate, final boolean untap, final int amount) {
-        List<Card> typeList = ai.getCardsIn(ZoneType.Battlefield);
-        typeList = CardLists.getValidCards(typeList, type.split(","), activate.getController(), activate);
+        List<Card> typeList = 
+                CardLists.getValidCards(ai.getCardsIn(ZoneType.Battlefield), type.split(","), activate.getController(), activate);
 
         // is this needed?
         typeList = CardLists.filter(typeList, Presets.TAPPED);
@@ -1735,14 +1734,10 @@ public class ComputerUtil {
      * @return a {@link forge.CardList} object.
      */
     public static List<Card> chooseReturnType(final Player ai, final String type, final Card activate, final Card target, final int amount) {
-        List<Card> typeList = ai.getCardsIn(ZoneType.Battlefield);
-        typeList = CardLists.getValidCards(typeList, type.split(","), activate.getController(), activate);
+        final List<Card> typeList = 
+                CardLists.getValidCards(ai.getCardsIn(ZoneType.Battlefield), type.split(","), activate.getController(), activate);
         if ((target != null) && target.getController().isComputer() && typeList.contains(target)) {
-            // bounce
-            // the
-            // card
-            // we're
-            // pumping
+            // don't bounce the card we're pumping
             typeList.remove(target);
         }
 
diff --git a/src/main/java/forge/game/player/ComputerUtilAttack.java b/src/main/java/forge/game/player/ComputerUtilAttack.java
index 545981ee911..98595e1a7a4 100644
--- a/src/main/java/forge/game/player/ComputerUtilAttack.java
+++ b/src/main/java/forge/game/player/ComputerUtilAttack.java
@@ -831,15 +831,12 @@ public class ComputerUtilAttack {
      * @return a int.
      */
     public final int countExaltedBonus(final Player player) {
-        List<Card> list = player.getCardsIn(ZoneType.Battlefield);
-        list = CardLists.filter(list, new Predicate<Card>() {
-            @Override
-            public boolean apply(final Card c) {
-                return c.hasKeyword("Exalted");
-            }
-        });
+        int bonus = 0;
+        for (Card c : player.getCardsIn(ZoneType.Battlefield)) {
+            bonus += c.getKeywordAmount("Exalted");
+        }
 
-        return list.size();
+        return bonus;
     }
 
     /**
diff --git a/src/main/java/forge/game/player/Player.java b/src/main/java/forge/game/player/Player.java
index 4f9b3d1f52d..b5821a4187c 100644
--- a/src/main/java/forge/game/player/Player.java
+++ b/src/main/java/forge/game/player/Player.java
@@ -1599,7 +1599,7 @@ public abstract class Player extends GameEntity implements Comparable<Player> {
      * @return the card list
      */
     public final List<Card> discardHand(final SpellAbility sa) {
-        final List<Card> list = this.getCardsIn(ZoneType.Hand);
+        final List<Card> list = new ArrayList<Card>(this.getCardsIn(ZoneType.Hand));
         this.discardRandom(list.size(), sa);
         return list;
     }
@@ -1648,8 +1648,8 @@ public abstract class Player extends GameEntity implements Comparable<Player> {
     public final List<Card> discardRandom(final int num, final SpellAbility sa, final String valid) {
         final List<Card> discarded = new ArrayList<Card>();
         for (int i = 0; i < num; i++) {
-            List<Card> list = this.getCardsIn(ZoneType.Hand);
-            list = CardLists.getValidCards(list, valid, sa.getSourceCard().getController(), sa.getSourceCard());
+            final List<Card> list = 
+                    CardLists.getValidCards(this.getCardsIn(ZoneType.Hand), valid, sa.getSourceCard().getController(), sa.getSourceCard());
             if (list.size() != 0) {
                 final Card disc = CardUtil.getRandom(list);
                 discarded.add(disc);
diff --git a/src/main/java/forge/gui/match/ControlWinLose.java b/src/main/java/forge/gui/match/ControlWinLose.java
index 4b942525bd7..fe30a65dc93 100644
--- a/src/main/java/forge/gui/match/ControlWinLose.java
+++ b/src/main/java/forge/gui/match/ControlWinLose.java
@@ -126,7 +126,7 @@ public class ControlWinLose {
                     continue; // not a loser
                 }
 
-                List<Card> compAntes = loser.getCardsIn(ZoneType.Ante);
+                List<Card> compAntes = new ArrayList<Card>(loser.getCardsIn(ZoneType.Ante));
                 Deck cDeck = match.getPlayersDeck(loser.getLobbyPlayer());
 
                 for (Card c : compAntes) {