* Gain abilities - fixed that objects can get only one instance of triggered ability instead multiple (example: 2+ cascades from copies of Imoti, Celebrant of Bounty, f52753ad61);

Mage.Tests/src/test/java/org/mage/test/cards/copy/CopySpellTest.java

@@ -404,4 +404,62 @@ public class CopySpellTest extends CardTestPlayerBase {
         assertPermanentCount(playerA, "Mountain", 1);
         assertPermanentCount(playerA, "Island", 1);
     }
+
+    @Test
+    public void test_AllowsMultipleInstancesOfGainedTriggers() {
+        // bug:  multiple copies of Imoti, Celebrant of Bounty only giving cascade once
+        // reason: gained ability used same id, so only one trigger were possible (now it uses new ids)
+        removeAllCardsFromHand(playerA);
+        removeAllCardsFromLibrary(playerA);
+        skipInitShuffling();
+
+        // Spells you cast with converted mana cost 6 or greater have cascade.
+        // Cascade
+        // (When you cast this spell exile cards from the top of your library until you exile a
+        // nonland card whose converted mana cost is less than this spell's converted mana cost. You may cast
+        // that spell without paying its mana cost if its converted mana cost is less than this spell's
+        // converted mana cost. Then put all cards exiled this way that weren't cast on the bottom of
+        // your library in a random order.)
+        addCard(Zone.BATTLEFIELD, playerA, "Imoti, Celebrant of Bounty", 1); // {3}{G}{U}
+        //
+        addCard(Zone.LIBRARY, playerA, "Swamp", 1);
+        addCard(Zone.LIBRARY, playerA, "Lightning Bolt", 1);
+        addCard(Zone.LIBRARY, playerA, "Swamp", 1);
+        addCard(Zone.LIBRARY, playerA, "Lightning Bolt", 1);
+        addCard(Zone.LIBRARY, playerA, "Swamp", 1);
+        //
+        // You may have Spark Double enter the battlefield as a copy of a creature or planeswalker you control,
+        // except it enters with an additional +1/+1 counter on it if it’s a creature, it enters with an
+        // additional loyalty counter on it if it’s a planeswalker, and it isn’t legendary if that
+        // permanent is legendary.
+        addCard(Zone.HAND, playerA, "Spark Double", 1); // {3}{U}
+        addCard(Zone.BATTLEFIELD, playerA, "Island", 4);
+        //
+        addCard(Zone.HAND, playerA, "Alpha Tyrranax", 1); // {4}{G}{G}
+        addCard(Zone.BATTLEFIELD, playerA, "Forest", 6);
+
+        // cast spark and make imoti's copy
+        castSpell(1, PhaseStep.PRECOMBAT_MAIN, playerA, "Spark Double");
+        setChoice(playerA, "Yes"); // use copy
+        setChoice(playerA, "Imoti, Celebrant of Bounty"); // copy of imoti
+        waitStackResolved(1, PhaseStep.PRECOMBAT_MAIN);
+        checkPermanentCount("after copy", 1, PhaseStep.PRECOMBAT_MAIN,  playerA, "Imoti, Celebrant of Bounty", 2);
+
+        // cast big spell and catch cascade 2x times (from two copies)
+        // possible bug: cascade activates only 1x times
+        castSpell(1, PhaseStep.PRECOMBAT_MAIN, playerA, "Alpha Tyrranax");
+        checkStackSize("afer big spell", 1, PhaseStep.PRECOMBAT_MAIN, playerA, 3);
+        setChoice(playerA, "cascade"); // choice between 2x gained cascades
+        setChoice(playerA, "Yes"); // cast first bolt by first cascade
+        addTarget(playerA, playerB); // target for first bolt
+        setChoice(playerA, "Yes"); // cast second bold by second cascade
+        addTarget(playerA, playerB); // target for second bolt
+
+        setStopAt(1, PhaseStep.END_TURN);
+        setStrictChooseMode(true);
+        execute();
+        assertAllCommandsUsed();
+
+        assertLife(playerB, 20 - 3 * 2); // 2x bolts from 2x cascades
+    }
 }

Mage/src/main/java/mage/abilities/AbilityImpl.java

@@ -142,6 +142,10 @@ public abstract class AbilityImpl implements Ability {
             this.id = UUID.randomUUID();
         }
         getEffects().newId();
+
+        for (Ability sub : getSubAbilities()) {
+            sub.newId();
+        }
     }
 
     @Override

Mage/src/main/java/mage/abilities/TriggeredAbilities.java

@@ -11,6 +11,7 @@ import mage.game.events.GameEvent;
 import mage.game.events.NumberOfTriggersEvent;
 import mage.game.permanent.Permanent;
 import mage.game.stack.Spell;
+import org.apache.log4j.Logger;
 
 /**
  * @author BetaSteward_at_googlemail.com
@@ -21,6 +22,8 @@ import mage.game.stack.Spell;
  */
 public class TriggeredAbilities extends ConcurrentHashMap<String, TriggeredAbility> {
 
+    private static final Logger logger = Logger.getLogger(TriggeredAbilities.class);
+
     private final Map<String, List<UUID>> sources = new HashMap<>();
 
     public TriggeredAbilities() {
@@ -115,7 +118,7 @@ public class TriggeredAbilities extends ConcurrentHashMap<String, TriggeredAbili
             this.add(ability, attachedTo);
             List<UUID> uuidList = new LinkedList<>();
             uuidList.add(sourceId);
-            // if the object that gained the ability moves zone, also then the triggered ability must be removed
+            // if the object that gained the ability moves from zone then the triggered ability must be removed
             uuidList.add(attachedTo.getId());
             sources.put(getKey(ability, attachedTo), uuidList);
         }

Mage/src/main/java/mage/abilities/effects/GainAbilitySpellsEffect.java

@@ -77,9 +77,6 @@ public class GainAbilitySpellsEffect extends ContinuousEffectImpl {
             if (card == null || !filter.match(stackObject, game)) {
                 continue;
             }
-            if (ability instanceof MageSingleton && card.hasAbility(ability, game)) {
-                continue;
-            }
             game.getState().addOtherAbility(card, ability);
         }
         return true;

Mage/src/main/java/mage/abilities/effects/common/continuous/GainAbilityControlledSpellsEffect.java

@@ -65,7 +65,8 @@ public class GainAbilityControlledSpellsEffect extends ContinuousEffectImpl {
             }
 
             // workaround to gain cost reduction abilities to commanders before cast (make it playable)
-            game.getCommanderCardsFromCommandZone(player, CommanderCardType.ANY).stream()
+            game.getCommanderCardsFromCommandZone(player, CommanderCardType.ANY)
+                    .stream()
                     .filter(card -> filter.match(card, game))
                     .forEach(card -> {
                         game.getState().addOtherAbility(card, ability);
@@ -77,12 +78,9 @@ public class GainAbilityControlledSpellsEffect extends ContinuousEffectImpl {
                         && !stackObject.isCopy()
                         && stackObject.isControlledBy(source.getControllerId())) {
                     Card card = game.getCard(stackObject.getSourceId());
-                    if (card != null
-                            && filter.match(card, game)) {
-                        if (!card.hasAbility(ability, game)) {
-                            game.getState().addOtherAbility(card, ability);
-                            return true;
-                        }
+                    if (card != null && filter.match(card, game)) {
+                        game.getState().addOtherAbility(card, ability);
+                        return true;
                     }
                 }
             }

Mage/src/main/java/mage/abilities/keyword/CascadeAbility.java

@@ -20,12 +20,33 @@ import java.util.List;
 import java.util.stream.Collectors;
 
 /**
+ * Cascade
+ * A keyword ability that may let a player cast a random extra spell for no cost. See rule 702.84, “Cascade.”
+ * <p>
+ * 702.84. Cascade
+ * <p>
+ * 702.84a Cascade is a triggered ability that functions only while the spell with cascade is on the stack.
+ * “Cascade” means “When you cast this spell, exile cards from the top of your library until you exile a
+ * nonland card whose converted mana cost is less than this spell’s converted mana cost. You may cast that
+ * card without paying its mana cost. Then put all cards exiled this way that weren’t cast on the bottom
+ * of your library in a random order.”
+ * <p>
+ * 702.84b If an effect allows a player to take an action with one or more of the exiled cards “as you cascade,”
+ * the player may take that action after they have finished exiling cards due to the cascade ability. This action
+ * is taken before choosing whether to cast the last exiled card or, if no appropriate card was exiled, before
+ * putting the exiled cards on the bottom of their library in a random order.
+ * <p>
+ * 702.84c If a spell has multiple instances of cascade, each triggers separately.
+ *
  * @author BetaSteward_at_googlemail.com
  */
 public class CascadeAbility extends TriggeredAbilityImpl {
     //20091005 - 702.82
     //20210215 - 702.84a - Updated Cascade rule
 
+    // can't use singletone due rules:
+    // 702.84c If a spell has multiple instances of cascade, each triggers separately.
+
     private static final String REMINDERTEXT = " <i>(When you cast this spell, "
             + "exile cards from the top of your library until you exile a "
             + "nonland card whose converted mana cost is less than this spell's converted mana cost. "

Mage/src/main/java/mage/abilities/keyword/SuspendAbility.java

@@ -180,13 +180,11 @@ public class SuspendAbility extends SpecialAction {
         ability1.setSourceId(card.getId());
         ability1.setControllerId(card.getOwnerId());
         game.getState().addOtherAbility(card, ability1);
-        game.getState().addAbility(ability1, source.getSourceId(), card);
 
         SuspendPlayCardAbility ability2 = new SuspendPlayCardAbility();
         ability2.setSourceId(card.getId());
         ability2.setControllerId(card.getOwnerId());
         game.getState().addOtherAbility(card, ability2);
-        game.getState().addAbility(ability2, source.getSourceId(), card);
     }
 
     public static UUID getSuspendExileId(UUID controllerId, Game game) {

Mage/src/main/java/mage/game/GameState.java

@@ -1081,7 +1081,8 @@ public class GameState implements Serializable, Copyable<GameState> {
      * @param attachedTo
      * @param ability
      * @param copyAbility copies non MageSingleton abilities before adding to
-     *                    state
+     *                    state (allows to have multiple instances in one object,
+     *                    e.g. false param will simulate keyword/singletone)
      */
     public void addOtherAbility(Card attachedTo, Ability ability, boolean copyAbility) {
         checkWrongDynamicAbilityUsage(attachedTo, ability);
@@ -1090,7 +1091,10 @@ public class GameState implements Serializable, Copyable<GameState> {
         if (ability instanceof MageSingleton || !copyAbility) {
             newAbility = ability;
         } else {
+            // must use new id, so you can add multiple instances of the same ability
+            // (example: gained Cascade from multiple Imoti, Celebrant of Bounty)
             newAbility = ability.copy();
+            newAbility.newId();
         }
         newAbility.setSourceId(attachedTo.getId());
         newAbility.setControllerId(attachedTo.getOwnerId());