diff --git a/Mage/src/main/java/mage/watchers/common/AmountOfDamageAPlayerReceivedThisTurnWatcher.java b/Mage/src/main/java/mage/watchers/common/AmountOfDamageAPlayerReceivedThisTurnWatcher.java
index fe994e1844e..23a4884150a 100644
--- a/Mage/src/main/java/mage/watchers/common/AmountOfDamageAPlayerReceivedThisTurnWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/AmountOfDamageAPlayerReceivedThisTurnWatcher.java
@@ -31,17 +31,16 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.UUID;
+
 import mage.constants.WatcherScope;
 import mage.game.Game;
 import mage.game.events.GameEvent;
 import mage.watchers.Watcher;
 
 /**
- *
  * @author jeffwadsworth
- *
- * Amount of damage received by a player this turn
- *
+ *         <p>
+ *         Amount of damage received by a player this turn
  */
 public class AmountOfDamageAPlayerReceivedThisTurnWatcher extends Watcher {
 
@@ -63,23 +62,14 @@ public class AmountOfDamageAPlayerReceivedThisTurnWatcher extends Watcher {
         if (event.getType() == GameEvent.EventType.DAMAGED_PLAYER) {
             UUID playerId = event.getTargetId();
             if (playerId != null) {
-                Integer amount = amountOfDamageReceivedThisTurn.get(playerId);
-                if (amount == null) {
-                    amount = event.getAmount();
-                } else {
-                    amount = amount + event.getAmount();
-                }
-                amountOfDamageReceivedThisTurn.put(playerId, amount);
+                amountOfDamageReceivedThisTurn.putIfAbsent(playerId, 0);
+                amountOfDamageReceivedThisTurn.compute(playerId, (k, v) -> v + event.getAmount());
             }
         }
     }
 
     public int getAmountOfDamageReceivedThisTurn(UUID playerId) {
-        Integer amount = amountOfDamageReceivedThisTurn.get(playerId);
-        if (amount != null) {
-            return amount;
-        }
-        return 0;
+        return amountOfDamageReceivedThisTurn.getOrDefault(playerId, 0);
     }
 
     @Override
diff --git a/Mage/src/main/java/mage/watchers/common/CardsAmountDrawnThisTurnWatcher.java b/Mage/src/main/java/mage/watchers/common/CardsAmountDrawnThisTurnWatcher.java
index b9f7d741547..ad0f8568d63 100644
--- a/Mage/src/main/java/mage/watchers/common/CardsAmountDrawnThisTurnWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/CardsAmountDrawnThisTurnWatcher.java
@@ -38,7 +38,6 @@ import java.util.Map;
 import java.util.UUID;
 
 /**
- *
  * @author Quercitron
  * @author LevelX2
  * @author jeffwadsworth
@@ -61,11 +60,8 @@ public class CardsAmountDrawnThisTurnWatcher extends Watcher {
     @Override
     public void watch(GameEvent event, Game game) {
         if (event.getType() == GameEvent.EventType.DREW_CARD) {
-            if (amountOfCardsDrawnThisTurn.containsKey(event.getPlayerId())) {
-                amountOfCardsDrawnThisTurn.put(event.getPlayerId(), amountOfCardsDrawnThisTurn.get(event.getPlayerId()) + 1);
-            } else {
-                amountOfCardsDrawnThisTurn.put(event.getPlayerId(), 1);
-            }
+            amountOfCardsDrawnThisTurn.putIfAbsent(event.getPlayerId(), 0);
+            amountOfCardsDrawnThisTurn.compute(event.getPlayerId(), (k, amount) -> amount += 1);
         }
     }
 
@@ -90,11 +86,7 @@ public class CardsAmountDrawnThisTurnWatcher extends Watcher {
     }
 
     public int getAmountCardsDrawn(UUID playerId) {
-        Integer amount = amountOfCardsDrawnThisTurn.get(playerId);
-        if (amount != null) {
-            return amount;
-        }
-        return 0;
+        return amountOfCardsDrawnThisTurn.getOrDefault(playerId,0);
     }
 
     @Override
diff --git a/Mage/src/main/java/mage/watchers/common/CardsDrawnDuringDrawStepWatcher.java b/Mage/src/main/java/mage/watchers/common/CardsDrawnDuringDrawStepWatcher.java
index 5a1e21cb5ba..8f213a336d1 100644
--- a/Mage/src/main/java/mage/watchers/common/CardsDrawnDuringDrawStepWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/CardsDrawnDuringDrawStepWatcher.java
@@ -32,6 +32,7 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.UUID;
+
 import mage.constants.PhaseStep;
 import mage.constants.WatcherScope;
 import mage.game.Game;
@@ -39,11 +40,9 @@ import mage.game.events.GameEvent;
 import mage.watchers.Watcher;
 
 /**
- *
  * @author LevelX2
- *
- * Counts cards drawn during draw step
- * 
+ *         <p>
+ *         Counts cards drawn during draw step
  */
 
 public class CardsDrawnDuringDrawStepWatcher extends Watcher {
@@ -65,26 +64,18 @@ public class CardsDrawnDuringDrawStepWatcher extends Watcher {
     public void watch(GameEvent event, Game game) {
         if (event.getType() == GameEvent.EventType.DREW_CARD
                 && game.getPhase() != null
-                && game.getPhase().getStep().getType().equals(PhaseStep.DRAW)) {
+                && game.getPhase().getStep().getType() == PhaseStep.DRAW) {
             UUID playerId = event.getPlayerId();
             if (playerId != null) {
-                Integer amount = amountOfCardsDrawnThisTurn.get(playerId);
-                if (amount == null) {
-                    amount = 1;
-                } else {
-                    amount++;
-                }
-                amountOfCardsDrawnThisTurn.put(playerId, amount);
+                amountOfCardsDrawnThisTurn.putIfAbsent(playerId, 0);
+                amountOfCardsDrawnThisTurn.compute(playerId, (k, amount) -> amount + 1);
+
             }
         }
     }
 
     public int getAmountCardsDrawn(UUID playerId) {
-        Integer amount = amountOfCardsDrawnThisTurn.get(playerId);
-        if (amount != null) {
-            return amount;
-        }
-        return 0;
+        return amountOfCardsDrawnThisTurn.getOrDefault(playerId, 0);
     }
 
     @Override
diff --git a/Mage/src/main/java/mage/watchers/common/CardsPutIntoGraveyardWatcher.java b/Mage/src/main/java/mage/watchers/common/CardsPutIntoGraveyardWatcher.java
index 4fbf9765f62..24957848cff 100644
--- a/Mage/src/main/java/mage/watchers/common/CardsPutIntoGraveyardWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/CardsPutIntoGraveyardWatcher.java
@@ -74,13 +74,9 @@ public class CardsPutIntoGraveyardWatcher extends Watcher {
         if (event.getType() == GameEvent.EventType.ZONE_CHANGE && ((ZoneChangeEvent) event).getToZone() == Zone.GRAVEYARD) {
             UUID playerId = event.getPlayerId();
             if (playerId != null && game.getCard(event.getTargetId()) != null) {
-                Integer amount = amountOfCardsThisTurn.get(playerId);
-                if (amount == null) {
-                    amount = 1;
-                } else {
-                    ++amount;
-                }
-                amountOfCardsThisTurn.put(playerId, amount);
+                amountOfCardsThisTurn.putIfAbsent(playerId, 0);
+                amountOfCardsThisTurn.compute(playerId, (k, amount) -> amount += 1);
+
                 if (((ZoneChangeEvent) event).getFromZone() == Zone.BATTLEFIELD) {
                     cardsPutToGraveyardFromBattlefield.add(new MageObjectReference(event.getTargetId(), game));
                 }
@@ -89,11 +85,7 @@ public class CardsPutIntoGraveyardWatcher extends Watcher {
     }
 
     public int getAmountCardsPutToGraveyard(UUID playerId) {
-        Integer amount = amountOfCardsThisTurn.get(playerId);
-        if (amount != null) {
-            return amount;
-        }
-        return 0;
+        return amountOfCardsThisTurn.getOrDefault(playerId, 0);
     }
 
     public Set<MageObjectReference> getCardsPutToGraveyardFromBattlefield() {
diff --git a/Mage/src/main/java/mage/watchers/common/CastFromHandWatcher.java b/Mage/src/main/java/mage/watchers/common/CastFromHandWatcher.java
index bf2d2f77b65..b52afa6ce89 100644
--- a/Mage/src/main/java/mage/watchers/common/CastFromHandWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/CastFromHandWatcher.java
@@ -4,6 +4,7 @@ import java.util.HashSet;
 import java.util.Objects;
 import java.util.Set;
 import java.util.UUID;
+
 import mage.constants.WatcherScope;
 import mage.constants.Zone;
 import mage.game.Game;
@@ -37,7 +38,7 @@ public class CastFromHandWatcher extends Watcher {
             spellsCastFromHand.clear();
             step = null;
         }
-        if (event.getType() == GameEvent.EventType.SPELL_CAST && event.getZone().equals(Zone.HAND)) {
+        if (event.getType() == GameEvent.EventType.SPELL_CAST && event.getZone() == Zone.HAND) {
             if (step == null) {
                 step = game.getTurn().getStep();
             }
diff --git a/Mage/src/main/java/mage/watchers/common/CastSpellLastTurnWatcher.java b/Mage/src/main/java/mage/watchers/common/CastSpellLastTurnWatcher.java
index 7e96ee21ea8..17e204b339d 100644
--- a/Mage/src/main/java/mage/watchers/common/CastSpellLastTurnWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/CastSpellLastTurnWatcher.java
@@ -27,20 +27,16 @@
  */
 package mage.watchers.common;
 
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Map.Entry;
-import java.util.UUID;
 import mage.MageObjectReference;
 import mage.constants.WatcherScope;
 import mage.game.Game;
 import mage.game.events.GameEvent;
 import mage.watchers.Watcher;
 
+import java.util.*;
+import java.util.Map.Entry;
+
 /**
- *
  * @author nantuko, BetaSteward_at_googlemail.com
  */
 public class CastSpellLastTurnWatcher extends Watcher {
@@ -70,13 +66,9 @@ public class CastSpellLastTurnWatcher extends Watcher {
             spellsCastThisTurnInOrder.add(new MageObjectReference(event.getTargetId(), game));
             UUID playerId = event.getPlayerId();
             if (playerId != null) {
-                Integer amount = amountOfSpellsCastOnCurrentTurn.get(playerId);
-                if (amount == null) {
-                    amount = 1;
-                } else {
-                    amount = amount + 1;
-                }
-                amountOfSpellsCastOnCurrentTurn.put(playerId, amount);
+                amountOfSpellsCastOnCurrentTurn.putIfAbsent(playerId, 0);
+                amountOfSpellsCastOnCurrentTurn.compute(playerId, (k, a) -> a + 1);
+
             }
         }
     }
@@ -98,20 +90,11 @@ public class CastSpellLastTurnWatcher extends Watcher {
     }
 
     public int getAmountOfSpellsAllPlayersCastOnCurrentTurn() {
-        int totalAmount = 0;
-        for (Integer amount : amountOfSpellsCastOnCurrentTurn.values()) {
-            totalAmount += amount;
-        }
-        return totalAmount;
+        return amountOfSpellsCastOnCurrentTurn.values().stream().mapToInt(Integer::intValue).sum();
     }
 
     public int getAmountOfSpellsPlayerCastOnCurrentTurn(UUID playerId) {
-        Integer value = amountOfSpellsCastOnCurrentTurn.get(playerId);
-        if (value != null) {
-            return value;
-        } else {
-            return 0;
-        }
+        return amountOfSpellsCastOnCurrentTurn.getOrDefault(playerId, 0);
     }
 
     public int getSpellOrder(MageObjectReference spell, Game game) {
diff --git a/Mage/src/main/java/mage/watchers/common/CommanderInfoWatcher.java b/Mage/src/main/java/mage/watchers/common/CommanderInfoWatcher.java
index 3f4b4f90fdf..769484331b2 100644
--- a/Mage/src/main/java/mage/watchers/common/CommanderInfoWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/CommanderInfoWatcher.java
@@ -77,10 +77,7 @@ public class CommanderInfoWatcher extends Watcher {
                 DamagedPlayerEvent damageEvent = (DamagedPlayerEvent) event;
                 if (damageEvent.isCombatDamage()) {
                     UUID playerUUID = event.getTargetId();
-                    Integer damage = damageToPlayer.get(playerUUID);
-                    if (damage == null) {
-                        damage = 0;
-                    }
+                    Integer damage = damageToPlayer.getOrDefault(playerUUID,0);
                     damage += damageEvent.getAmount();
                     damageToPlayer.put(playerUUID, damage);
                     Player player = game.getPlayer(playerUUID);
diff --git a/Mage/src/main/java/mage/watchers/common/CreaturesDiedWatcher.java b/Mage/src/main/java/mage/watchers/common/CreaturesDiedWatcher.java
index 12daad0fc01..669d37026d6 100644
--- a/Mage/src/main/java/mage/watchers/common/CreaturesDiedWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/CreaturesDiedWatcher.java
@@ -81,10 +81,7 @@ public class CreaturesDiedWatcher extends Watcher {
     }
 
     public int getAmountOfCreaturesDiesThisTurn(UUID playerId) {
-        if (amountOfCreaturesThatDiedByController.containsKey(playerId)) {
-            return amountOfCreaturesThatDiedByController.get(playerId);
-        }
-        return 0;
+        return amountOfCreaturesThatDiedByController.getOrDefault(playerId, 0);
     }
 
     @Override
diff --git a/Mage/src/main/java/mage/watchers/common/DamageDoneWatcher.java b/Mage/src/main/java/mage/watchers/common/DamageDoneWatcher.java
index d30882f7427..d9df669f884 100644
--- a/Mage/src/main/java/mage/watchers/common/DamageDoneWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/DamageDoneWatcher.java
@@ -5,17 +5,17 @@
  */
 package mage.watchers.common;
 
-import java.util.HashMap;
-import java.util.Map;
-import java.util.UUID;
 import mage.MageObjectReference;
 import mage.constants.WatcherScope;
 import mage.game.Game;
 import mage.game.events.GameEvent;
 import mage.watchers.Watcher;
 
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+
 /**
- *
  * @author LevelX2
  */
 public class DamageDoneWatcher extends Watcher {
@@ -50,12 +50,12 @@ public class DamageDoneWatcher extends Watcher {
             case DAMAGED_PLANESWALKER:
             case DAMAGED_PLAYER: {
                 MageObjectReference damageSourceRef = new MageObjectReference(event.getSourceId(), game);
-                int damageDone = damagingObjects.containsKey(damageSourceRef) ? damagingObjects.get(damageSourceRef) : 0;
-                damagingObjects.put(damageSourceRef, damageDone + event.getAmount());
+                damagingObjects.putIfAbsent(damageSourceRef, 0);
+                damagingObjects.compute(damageSourceRef, (k, damage) -> damage + event.getAmount());
 
                 MageObjectReference damageTargetRef = new MageObjectReference(event.getTargetId(), game);
-                int damageReceived = damagedObjects.containsKey(damageTargetRef) ? damagedObjects.get(damageTargetRef) : 0;
-                damagedObjects.put(damageTargetRef, damageReceived + event.getAmount());
+                damagedObjects.putIfAbsent(damageTargetRef, 0);
+                damagedObjects.compute(damageTargetRef, (k, damage) -> damage + event.getAmount());
             }
         }
     }
@@ -69,12 +69,12 @@ public class DamageDoneWatcher extends Watcher {
 
     public int damageDoneBy(UUID objectId, int zoneChangeCounter, Game game) {
         MageObjectReference mor = new MageObjectReference(objectId, zoneChangeCounter, game);
-        return damagingObjects.containsKey(mor) ? damagingObjects.get(mor) : 0;
+        return damagingObjects.getOrDefault(mor, 0);
     }
 
     public int damageDoneTo(UUID objectId, int zoneChangeCounter, Game game) {
         MageObjectReference mor = new MageObjectReference(objectId, zoneChangeCounter, game);
-        return damagedObjects.containsKey(mor) ? damagedObjects.get(mor) : 0;
+        return damagedObjects.getOrDefault(mor, 0);
     }
 
     public boolean isDamaged(UUID objectId, int zoneChangeCounter, Game game) {
diff --git a/Mage/src/main/java/mage/watchers/common/DamagedByWatcher.java b/Mage/src/main/java/mage/watchers/common/DamagedByWatcher.java
index 0043bc03dea..00816564e91 100644
--- a/Mage/src/main/java/mage/watchers/common/DamagedByWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/DamagedByWatcher.java
@@ -30,6 +30,7 @@ package mage.watchers.common;
 import java.util.HashSet;
 import java.util.Set;
 import java.util.UUID;
+
 import mage.MageObject;
 import mage.MageObjectReference;
 import mage.constants.WatcherScope;
@@ -40,7 +41,6 @@ import mage.game.permanent.Permanent;
 import mage.watchers.Watcher;
 
 /**
- *
  * @author BetaSteward_at_googlemail.com
  */
 public class DamagedByWatcher extends Watcher {
@@ -72,12 +72,11 @@ public class DamagedByWatcher extends Watcher {
     @Override
     public void watch(GameEvent event, Game game) {
         boolean eventHasAppropriateType = (event.getType() == EventType.DAMAGED_CREATURE) ||
-                                          (watchPlaneswalkers && event.getType() == EventType.DAMAGED_PLANESWALKER);
+                (watchPlaneswalkers && event.getType() == EventType.DAMAGED_PLANESWALKER);
         if (eventHasAppropriateType && sourceId.equals(event.getSourceId())) {
             MageObjectReference mor = new MageObjectReference(event.getTargetId(), game);
-            if (!damagedBySource.contains(mor)) {
-                damagedBySource.add(mor);
-            }
+            damagedBySource.add(mor);
+
         }
     }
 
diff --git a/Mage/src/main/java/mage/watchers/common/FirstSpellCastThisTurnWatcher.java b/Mage/src/main/java/mage/watchers/common/FirstSpellCastThisTurnWatcher.java
index 145bd9abf05..0c4a6f0ae3f 100644
--- a/Mage/src/main/java/mage/watchers/common/FirstSpellCastThisTurnWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/FirstSpellCastThisTurnWatcher.java
@@ -3,6 +3,7 @@ package mage.watchers.common;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.UUID;
+
 import mage.constants.WatcherScope;
 import mage.game.Game;
 import mage.game.events.GameEvent;
@@ -12,7 +13,6 @@ import mage.watchers.Watcher;
 
 /**
  * @author jeffwadsworth
-*
  */
 public class FirstSpellCastThisTurnWatcher extends Watcher {
 
@@ -36,9 +36,9 @@ public class FirstSpellCastThisTurnWatcher extends Watcher {
             case CAST_SPELL:
                 Spell spell = (Spell) game.getObject(event.getTargetId());
                 if (spell != null && !playerFirstSpellCast.containsKey(spell.getControllerId())) {
-                    if (event.getType().equals(EventType.SPELL_CAST)) {
+                    if (event.getType() == EventType.SPELL_CAST) {
                         playerFirstSpellCast.put(spell.getControllerId(), spell.getId());
-                    } else if (event.getType().equals(EventType.CAST_SPELL)) {
+                    } else if (event.getType() == EventType.CAST_SPELL) {
                         playerFirstCastSpell.put(spell.getControllerId(), spell.getId());
                     }
                 }
@@ -58,10 +58,6 @@ public class FirstSpellCastThisTurnWatcher extends Watcher {
     }
 
     public UUID getIdOfFirstCastSpell(UUID playerId) {
-        if (playerFirstSpellCast.get(playerId) == null) {
-            return playerFirstCastSpell.get(playerId);
-        } else {
-            return playerFirstSpellCast.get(playerId);
-        }
+        return playerFirstSpellCast.getOrDefault(playerId, playerFirstSpellCast.get(playerId));
     }
 }
diff --git a/Mage/src/main/java/mage/watchers/common/ManaSpentToCastWatcher.java b/Mage/src/main/java/mage/watchers/common/ManaSpentToCastWatcher.java
index 2577498b4e5..d00e66597c3 100644
--- a/Mage/src/main/java/mage/watchers/common/ManaSpentToCastWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/ManaSpentToCastWatcher.java
@@ -39,7 +39,6 @@ import mage.watchers.Watcher;
 /**
  * Watcher saves the mana that was spent to cast a spell
  *
- *
  * @author LevelX2
  */
 public class ManaSpentToCastWatcher extends Watcher {
@@ -64,7 +63,7 @@ public class ManaSpentToCastWatcher extends Watcher {
             }
         }
         if (event.getType() == GameEvent.EventType.ZONE_CHANGE && this.getSourceId().equals(event.getSourceId())) {
-            if (((ZoneChangeEvent) event).getFromZone().equals(Zone.BATTLEFIELD)) {
+            if (((ZoneChangeEvent) event).getFromZone() == Zone.BATTLEFIELD) {
                 payment = null;
             }
         }
diff --git a/Mage/src/main/java/mage/watchers/common/MiracleWatcher.java b/Mage/src/main/java/mage/watchers/common/MiracleWatcher.java
index d9816918777..f5ff489e4b0 100644
--- a/Mage/src/main/java/mage/watchers/common/MiracleWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/MiracleWatcher.java
@@ -31,6 +31,7 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.UUID;
+
 import mage.abilities.Ability;
 import mage.abilities.keyword.MiracleAbility;
 import mage.cards.Card;
@@ -74,14 +75,9 @@ public class MiracleWatcher extends Watcher {
         if (game.getPhase() != null && event.getType() == GameEvent.EventType.DREW_CARD) {
             UUID playerId = event.getPlayerId();
             if (playerId != null) {
-                Integer amount = amountOfCardsDrawnThisTurn.get(playerId);
-                if (amount == null) {
-                    amount = 1;
-                } else {
-                    amount++;
-                }
-                amountOfCardsDrawnThisTurn.put(playerId, amount);
-                if (amount == 1) {
+                amountOfCardsDrawnThisTurn.putIfAbsent(playerId, 0);
+                amountOfCardsDrawnThisTurn.compute(playerId, (p, amount) -> amount + 1);
+                if (amountOfCardsDrawnThisTurn.get(playerId) == 1) {
                     checkMiracleAbility(event, game);
                 }
             }
diff --git a/Mage/src/main/java/mage/watchers/common/PlayerAttackedWatcher.java b/Mage/src/main/java/mage/watchers/common/PlayerAttackedWatcher.java
index 0b3d231a101..96e1f892095 100644
--- a/Mage/src/main/java/mage/watchers/common/PlayerAttackedWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/PlayerAttackedWatcher.java
@@ -66,8 +66,8 @@ public class PlayerAttackedWatcher extends Watcher {
     @Override
     public void watch(GameEvent event, Game game) {
         if (event.getType() == GameEvent.EventType.ATTACKER_DECLARED) {
-            int numberAttackers = playerAttacked.containsKey(event.getPlayerId()) ? playerAttacked.get(event.getPlayerId()) : 0;
-            playerAttacked.put(event.getPlayerId(), numberAttackers + 1);
+            playerAttacked.putIfAbsent(event.getPlayerId(), 0);
+            playerAttacked.compute(event.getPlayerId(), (p,amount)->amount + 1);
         }
     }
 
@@ -78,6 +78,6 @@ public class PlayerAttackedWatcher extends Watcher {
     }
 
     public int getNumberOfAttackersCurrentTurn(UUID playerId) {
-        return playerAttacked.containsKey(playerId) ? playerAttacked.get(playerId) : 0;
+        return playerAttacked.getOrDefault(playerId, 0);
     }
 }
diff --git a/Mage/src/main/java/mage/watchers/common/PlayerGainedLifeWatcher.java b/Mage/src/main/java/mage/watchers/common/PlayerGainedLifeWatcher.java
index cc26a60ab89..f3e9039c39e 100644
--- a/Mage/src/main/java/mage/watchers/common/PlayerGainedLifeWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/PlayerGainedLifeWatcher.java
@@ -65,23 +65,14 @@ public class PlayerGainedLifeWatcher extends Watcher {
         if (event.getType() == GameEvent.EventType.GAINED_LIFE) {
             UUID playerId = event.getPlayerId();
             if (playerId != null) {
-                Integer amount = amountOfLifeGainedThisTurn.get(playerId);
-                if (amount == null) {
-                    amount = event.getAmount();
-                } else {
-                    amount = amount + event.getAmount();
-                }
-                amountOfLifeGainedThisTurn.put(playerId, amount);
+                amountOfLifeGainedThisTurn.putIfAbsent(playerId, 0);
+                amountOfLifeGainedThisTurn.compute(playerId, (p, amount) -> amount +event.getAmount());
             }
         }
     }
 
     public int getLiveGained(UUID playerId) {
-        Integer amount = amountOfLifeGainedThisTurn.get(playerId);
-        if (amount != null) {
-            return amount;
-        }
-        return 0;
+        return amountOfLifeGainedThisTurn.getOrDefault(playerId, 0);
     }
 
     @Override
diff --git a/Mage/src/main/java/mage/watchers/common/PlayerLostLifeWatcher.java b/Mage/src/main/java/mage/watchers/common/PlayerLostLifeWatcher.java
index b07e66b75d5..44db03d8bb4 100644
--- a/Mage/src/main/java/mage/watchers/common/PlayerLostLifeWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/PlayerLostLifeWatcher.java
@@ -75,19 +75,11 @@ public class PlayerLostLifeWatcher extends Watcher {
     }
 
     public int getLiveLost(UUID playerId) {
-        Integer amount = amountOfLifeLostThisTurn.get(playerId);
-        if (amount != null) {
-            return amount;
-        }
-        return 0;
+        return amountOfLifeLostThisTurn.getOrDefault(playerId, 0);
     }
 
     public int getLiveLostLastTurn(UUID playerId) {
-        Integer amount = amountOfLifeLostLastTurn.get(playerId);
-        if (amount != null) {
-            return amount;
-        }
-        return 0;
+        return amountOfLifeLostLastTurn.getOrDefault(playerId, 0);
     }
 
     @Override
diff --git a/Mage/src/main/java/mage/watchers/common/ProwlWatcher.java b/Mage/src/main/java/mage/watchers/common/ProwlWatcher.java
index ab3a4c0e668..7f6d5f86f86 100644
--- a/Mage/src/main/java/mage/watchers/common/ProwlWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/ProwlWatcher.java
@@ -80,10 +80,8 @@ public class ProwlWatcher extends Watcher {
                     if (creature.getAbilities().containsKey(ChangelingAbility.getInstance().getId()) || creature.getSubtype(game).contains(ChangelingAbility.ALL_CREATURE_TYPE)) {
                         allSubtypes.add(creature.getControllerId());
                     } else {
-                        Set<String> subtypes = damagingSubtypes.get(creature.getControllerId());
-                        if (subtypes == null) {
-                            subtypes = new LinkedHashSet<>();
-                        }
+                        Set<String> subtypes = damagingSubtypes.getOrDefault(creature.getControllerId(), new LinkedHashSet<>());
+
                         subtypes.addAll(creature.getSubtype(game));
                         damagingSubtypes.put(creature.getControllerId(), subtypes);
                     }
diff --git a/Mage/src/main/java/mage/watchers/common/SourceDidDamageWatcher.java b/Mage/src/main/java/mage/watchers/common/SourceDidDamageWatcher.java
index 7e01b65dd1b..4c5ee497b5a 100644
--- a/Mage/src/main/java/mage/watchers/common/SourceDidDamageWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/SourceDidDamageWatcher.java
@@ -33,9 +33,7 @@ import mage.game.events.GameEvent;
 import mage.game.events.GameEvent.EventType;
 import mage.watchers.Watcher;
 
-import java.util.ArrayList;
-import java.util.List;
-import java.util.UUID;
+import java.util.*;
 
 /**
  * Watcher stores which sources did damage to anything.
@@ -44,7 +42,7 @@ import java.util.UUID;
  */
 public class SourceDidDamageWatcher extends Watcher {
 
-    public final List<UUID> damageSources = new ArrayList<>();
+    public final Set<UUID> damageSources = new HashSet<>();
 
     public SourceDidDamageWatcher() {
         super("SourceDidDamageWatcher", WatcherScope.GAME);
@@ -65,9 +63,8 @@ public class SourceDidDamageWatcher extends Watcher {
         if (event.getType() == EventType.DAMAGED_CREATURE
                 || event.getType() == EventType.DAMAGED_PLANESWALKER
                 || event.getType() == EventType.DAMAGED_PLAYER) {
-            if (!damageSources.contains(event.getSourceId())) {
                 damageSources.add(event.getSourceId());
-            }
+
         }
     }