diff --git a/Mage.Server.Plugins/Mage.Player.AI.MA/src/mage/player/ai/util/CombatUtil.java b/Mage.Server.Plugins/Mage.Player.AI.MA/src/mage/player/ai/util/CombatUtil.java
index b292321382a..5929577fbe4 100644
--- a/Mage.Server.Plugins/Mage.Player.AI.MA/src/mage/player/ai/util/CombatUtil.java
+++ b/Mage.Server.Plugins/Mage.Player.AI.MA/src/mage/player/ai/util/CombatUtil.java
@@ -23,7 +23,7 @@ import java.util.*;
  */
 public final class CombatUtil {
 
-    private static final List<Permanent> emptyList = new ArrayList<>();
+    private static final List<Permanent> emptyList = Collections.unmodifiableList(new ArrayList<>());
 
     private static final Logger log = Logger.getLogger(CombatUtil.class);
 
diff --git a/Mage.Sets/src/mage/cards/c/CodespellCleric.java b/Mage.Sets/src/mage/cards/c/CodespellCleric.java
index 15b743e83d2..43ecf236cfa 100644
--- a/Mage.Sets/src/mage/cards/c/CodespellCleric.java
+++ b/Mage.Sets/src/mage/cards/c/CodespellCleric.java
@@ -71,7 +71,7 @@ enum CodespellClericCondition implements Condition {
 class CodespellClericWatcher extends Watcher {
 
     private final Map<UUID, List<MageObjectReference>> spellMap = new HashMap<>();
-    private static final List<MageObjectReference> emptyList = new ArrayList<>();
+    private static final List<MageObjectReference> emptyList = Collections.unmodifiableList(new ArrayList<>());
 
     CodespellClericWatcher() {
         super(WatcherScope.GAME);
diff --git a/Mage.Sets/src/mage/cards/h/HotheadedGiant.java b/Mage.Sets/src/mage/cards/h/HotheadedGiant.java
index 91ba66f331a..7cc5bc62fb9 100644
--- a/Mage.Sets/src/mage/cards/h/HotheadedGiant.java
+++ b/Mage.Sets/src/mage/cards/h/HotheadedGiant.java
@@ -57,7 +57,7 @@ public final class HotheadedGiant extends CardImpl {
 class HotheadedGiantWatcher extends Watcher {
 
     private final Map<UUID, List<MageObjectReference>> spellMap = new HashMap<>();
-    private static final List<MageObjectReference> emptyList = new ArrayList<>();
+    private static final List<MageObjectReference> emptyList = Collections.unmodifiableList(new ArrayList<>());
 
     HotheadedGiantWatcher() {
         super(WatcherScope.GAME);
diff --git a/Mage.Sets/src/mage/cards/s/SoulReap.java b/Mage.Sets/src/mage/cards/s/SoulReap.java
index e555ecec3d6..ad752ed5905 100644
--- a/Mage.Sets/src/mage/cards/s/SoulReap.java
+++ b/Mage.Sets/src/mage/cards/s/SoulReap.java
@@ -91,7 +91,7 @@ class SoulReapEffect extends OneShotEffect {
 class SoulReapWatcher extends Watcher {
 
     private final Map<UUID, List<MageObjectReference>> spellMap = new HashMap<>();
-    private static final List<MageObjectReference> emptyList = new ArrayList<>();
+    private static final List<MageObjectReference> emptyList = Collections.unmodifiableList(new ArrayList<>());
 
     SoulReapWatcher() {
         super(WatcherScope.GAME);
diff --git a/Mage/src/main/java/mage/designations/Designation.java b/Mage/src/main/java/mage/designations/Designation.java
index 059968951f1..668940ac427 100644
--- a/Mage/src/main/java/mage/designations/Designation.java
+++ b/Mage/src/main/java/mage/designations/Designation.java
@@ -18,17 +18,14 @@ import mage.game.events.ZoneChangeEvent;
 import mage.util.GameLog;
 import mage.util.SubTypes;
 
-import java.util.ArrayList;
-import java.util.EnumSet;
-import java.util.List;
-import java.util.UUID;
+import java.util.*;
 
 /**
  * @author LevelX2
  */
 public abstract class Designation implements MageObject {
 
-    private static final List<CardType> emptySet = new ArrayList<>();
+    private static final List<CardType> emptyList = Collections.unmodifiableList(new ArrayList<>());
     private static final ObjectColor emptyColor = new ObjectColor();
     private static final ManaCostsImpl emptyCost = new ManaCostsImpl<>();
 
@@ -155,7 +152,7 @@ public abstract class Designation implements MageObject {
 
     @Override
     public List<CardType> getCardType(Game game) {
-        return emptySet;
+        return emptyList;
     }
 
     @Override
diff --git a/Mage/src/main/java/mage/game/command/Dungeon.java b/Mage/src/main/java/mage/game/command/Dungeon.java
index 5d8a470e1eb..b7987c90ed6 100644
--- a/Mage/src/main/java/mage/game/command/Dungeon.java
+++ b/Mage/src/main/java/mage/game/command/Dungeon.java
@@ -45,7 +45,7 @@ public class Dungeon implements CommandObject {
         dungeonNames.add("Dungeon of the Mad Mage");
     }
 
-    private static final List<CardType> emptySet = Arrays.asList(CardType.DUNGEON);
+    private static final List<CardType> emptyList = Collections.unmodifiableList(Arrays.asList(CardType.DUNGEON));
     private static final ObjectColor emptyColor = new ObjectColor();
     private static final ManaCosts<ManaCost> emptyCost = new ManaCostsImpl<>();
 
@@ -240,7 +240,7 @@ public class Dungeon implements CommandObject {
 
     @Override
     public List<CardType> getCardType(Game game) {
-        return emptySet;
+        return emptyList;
     }
 
     @Override
diff --git a/Mage/src/main/java/mage/game/command/Emblem.java b/Mage/src/main/java/mage/game/command/Emblem.java
index 06cf459ca7c..0f810ce3325 100644
--- a/Mage/src/main/java/mage/game/command/Emblem.java
+++ b/Mage/src/main/java/mage/game/command/Emblem.java
@@ -22,19 +22,16 @@ import mage.util.GameLog;
 import mage.util.RandomUtil;
 import mage.util.SubTypes;
 
-import java.util.ArrayList;
-import java.util.EnumSet;
-import java.util.List;
-import java.util.UUID;
+import java.util.*;
 
 /**
  * @author nantuko
  */
 public class Emblem implements CommandObject {
 
-    private static List<CardType> emptySet = new ArrayList<>();
-    private static ObjectColor emptyColor = new ObjectColor();
-    private static ManaCosts emptyCost = new ManaCostsImpl<>();
+    private static final List<CardType> emptyList = Collections.unmodifiableList(new ArrayList<>());
+    private static final ObjectColor emptyColor = new ObjectColor();
+    private static final ManaCosts emptyCost = new ManaCostsImpl<>();
 
     private String name = "";
     private UUID id;
@@ -159,7 +156,7 @@ public class Emblem implements CommandObject {
 
     @Override
     public List<CardType> getCardType(Game game) {
-        return emptySet;
+        return emptyList;
     }
 
     @Override
diff --git a/Mage/src/main/java/mage/game/command/Plane.java b/Mage/src/main/java/mage/game/command/Plane.java
index a3a3c31e649..9241735c750 100644
--- a/Mage/src/main/java/mage/game/command/Plane.java
+++ b/Mage/src/main/java/mage/game/command/Plane.java
@@ -24,19 +24,16 @@ import mage.util.RandomUtil;
 import mage.util.SubTypes;
 
 import java.lang.reflect.Constructor;
-import java.util.ArrayList;
-import java.util.EnumSet;
-import java.util.List;
-import java.util.UUID;
+import java.util.*;
 
 /**
  * @author spjspj
  */
 public class Plane implements CommandObject {
 
-    private static List<CardType> emptySet = new ArrayList<>();
-    private static ObjectColor emptyColor = new ObjectColor();
-    private static ManaCosts emptyCost = new ManaCostsImpl<>();
+    private static final List<CardType> emptyList = Collections.unmodifiableList(new ArrayList<>());
+    private static final ObjectColor emptyColor = new ObjectColor();
+    private static final ManaCosts emptyCost = new ManaCostsImpl<>();
 
     private Planes planeType = null;
     private UUID id;
@@ -158,7 +155,7 @@ public class Plane implements CommandObject {
 
     @Override
     public List<CardType> getCardType(Game game) {
-        return emptySet;
+        return emptyList;
     }
 
     @Override
diff --git a/Mage/src/main/java/mage/game/stack/StackAbility.java b/Mage/src/main/java/mage/game/stack/StackAbility.java
index d0f9baffb88..9381716f60a 100644
--- a/Mage/src/main/java/mage/game/stack/StackAbility.java
+++ b/Mage/src/main/java/mage/game/stack/StackAbility.java
@@ -34,18 +34,15 @@ import mage.util.SubTypes;
 import mage.util.functions.StackObjectCopyApplier;
 import mage.watchers.Watcher;
 
-import java.util.ArrayList;
-import java.util.EnumSet;
-import java.util.List;
-import java.util.UUID;
+import java.util.*;
 
 /**
  * @author BetaSteward_at_googlemail.com
  */
 public class StackAbility extends StackObjectImpl implements Ability {
 
-    private static final List<CardType> emptyCardType = new ArrayList<>();
-    private static final List<String> emptyString = new ArrayList<>();
+    private static final List<CardType> emptyCardType = Collections.unmodifiableList(new ArrayList<>());
+    private static final List<String> emptyString = Collections.unmodifiableList(new ArrayList<>());
     private static final ObjectColor emptyColor = new ObjectColor();
     private static final ManaCosts<ManaCost> emptyCost = new ManaCostsImpl<>();
     private static final Costs<Cost> emptyCosts = new CostsImpl<>();