- Improved the AI logic for MustBlock a little.

- Enabled several cards for the AI.
- Implemented Sisters of Stone Death's 3rd ability similar to Tomb of the Dusk Rose which the AI can properly work with (seems functionally identical).
- Fixed the AI logic spec for Tomb of the Dusk Rose.

forge-ai/src/main/java/forge/ai/ability/MustBlockAi.java

@@ -2,15 +2,16 @@ package forge.ai.ability;
 
 import com.google.common.base.Predicate;
 
-import forge.ai.ComputerUtil;
+import com.google.common.collect.Lists;
-import forge.ai.ComputerUtilCard;
+import forge.ai.*;
-import forge.ai.ComputerUtilCombat;
+import forge.game.Game;
-import forge.ai.SpellAbilityAi;
 import forge.game.ability.AbilityUtils;
 import forge.game.card.Card;
 import forge.game.card.CardLists;
 import forge.game.card.CardPredicates;
+import forge.game.combat.Combat;
 import forge.game.combat.CombatUtil;
+import forge.game.phase.PhaseHandler;
 import forge.game.phase.PhaseType;
 import forge.game.player.Player;
 import forge.game.spellability.SpellAbility;
@@ -23,14 +24,45 @@ public class MustBlockAi extends SpellAbilityAi {
 
     @Override
     protected boolean canPlayAI(Player aiPlayer, SpellAbility sa) {
-        // disabled for the AI until he/she can make decisions about who to make
+        final Card source = sa.getHostCard();
-        // block
+        final Game game = aiPlayer.getGame();
+        final Combat combat = game.getCombat();
+        final PhaseHandler ph = game.getPhaseHandler();
+        final boolean onlyLethal = !"AllowNonLethal".equals(sa.getParam("AILogic"));
+
+        if (combat == null || !combat.isAttacking(source)) {
+            return false;
+        } else if (AiCardMemory.isRememberedCard(aiPlayer, source, AiCardMemory.MemorySet.ACTIVATED_THIS_TURN)) {
+            // The AI can meaningfully do it only to one creature per card yet, trying to do it to multiple cards
+            // may result in overextending and losing the attacker
+            return false;
+        }
+
+        final TargetRestrictions abTgt = sa.getTargetRestrictions();
+        final List<Card> list = determineGoodBlockers(source, aiPlayer, combat.getDefenderPlayerByAttacker(source), sa, onlyLethal,false);
+
+        if (!list.isEmpty()) {
+            final Card blocker = ComputerUtilCard.getBestCreatureAI(list);
+            if (blocker == null) {
+                return false;
+            }
+            sa.getTargets().add(blocker);
+            AiCardMemory.rememberCard(aiPlayer, source, AiCardMemory.MemorySet.ACTIVATED_THIS_TURN);
+            return true;
+        }
+
         return false;
     }
 
     @Override
     public boolean chkAIDrawback(SpellAbility sa, Player aiPlayer) {
-        return false;
+        if (sa.hasParam("DefinedAttacker")) {
+            // The AI can't handle "target creature blocks another target creature" abilities yet
+            return false;
+        }
+
+        // Otherwise it's a standard targeted "target creature blocks CARDNAME" ability, so use the main canPlayAI code path
+        return canPlayAI(aiPlayer, sa);
     }
 
     @Override
@@ -62,27 +94,7 @@ public class MustBlockAi extends SpellAbilityAi {
         boolean chance = false;
 
         if (abTgt != null) {
-            List<Card> list = CardLists.filter(ComputerUtil.getOpponentFor(ai).getCardsIn(ZoneType.Battlefield), CardPredicates.Presets.CREATURES);
+            final List<Card> list = determineGoodBlockers(definedAttacker, ai, ComputerUtil.getOpponentFor(ai), sa, true,true);
-            list = CardLists.getTargetableCards(list, sa);
-            list = CardLists.getValidCards(list, abTgt.getValidTgts(), source.getController(), source, sa);
-            list = CardLists.filter(list, new Predicate<Card>() {
-                @Override
-                public boolean apply(final Card c) {
-                    boolean tapped = c.isTapped();
-                    c.setTapped(false);
-                    if (!CombatUtil.canBlock(definedAttacker, c)) {
-                        return false;
-                    }
-                    if (ComputerUtilCombat.canDestroyAttacker(ai, definedAttacker, c, null, false)) {
-                        return false;
-                    }
-                    if (!ComputerUtilCombat.canDestroyBlocker(ai, c, definedAttacker, null, false)) {
-                        return false;
-                    }
-                    c.setTapped(tapped);
-                    return true;
-                }
-            });
             if (list.isEmpty()) {
                 return false;
             }
@@ -98,4 +110,39 @@ public class MustBlockAi extends SpellAbilityAi {
 
         return chance;
     }
+
+    private List<Card> determineGoodBlockers(Card attacker, Player ai, Player defender, SpellAbility sa, boolean onlyLethal, boolean testTapped) {
+        final Card source = sa.getHostCard();
+        final TargetRestrictions abTgt = sa.getTargetRestrictions();
+
+        List<Card> list = Lists.newArrayList();
+        list = CardLists.filter(defender.getCardsIn(ZoneType.Battlefield), CardPredicates.Presets.CREATURES);
+        list = CardLists.getTargetableCards(list, sa);
+        list = CardLists.getValidCards(list, abTgt.getValidTgts(), source.getController(), source, sa);
+        list = CardLists.filter(list, new Predicate<Card>() {
+            @Override
+            public boolean apply(final Card c) {
+                boolean tapped = c.isTapped();
+                if (testTapped) {
+                    c.setTapped(false);
+                }
+                if (!CombatUtil.canBlock(attacker, c)) {
+                    return false;
+                }
+                if (ComputerUtilCombat.canDestroyAttacker(ai, attacker, c, null, false)) {
+                    return false;
+                }
+                if (onlyLethal && !ComputerUtilCombat.canDestroyBlocker(ai, c, attacker, null, false)) {
+                    return false;
+                }
+                if (testTapped) {
+                    c.setTapped(tapped);
+                }
+                return true;
+            }
+
+        });
+
+        return list;
+    }
 }

forge-gui/res/cardsfolder/l/lurking_arynx.txt

@@ -4,6 +4,5 @@ Types:Creature Cat Beast
 PT:3/5
 A:AB$ MustBlock | Cost$ 2 G | ValidTgts$ Creature | CheckSVar$ FormidableTest | SVarCompare$ GE8 | References$ FormidableTest | PrecostDesc$ Formidable — | TgtPrompt$ Select target creature that must block this creature this turn | SpellDescription$ Target creature blocks CARDNAME this turn if able. Activate this ability only if creatures you control have total power 8 or greater.
 SVar:FormidableTest:Count$SumPower_Creature.YouCtrl
-AI:RemoveDeck:All
 SVar:Picture:http://www.wizards.com/global/images/magic/general/lurking_arynx.jpg
 Oracle:Formidable — {2}{G}: Target creature blocks Lurking Arynx this turn if able. Activate this ability only if creatures you control have total power 8 or greater.

forge-gui/res/cardsfolder/m/matsu_tribe_decoy.txt

@@ -2,7 +2,7 @@ Name:Matsu-Tribe Decoy
 ManaCost:2 G
 Types:Creature Snake Warrior
 PT:1/3
-A:AB$ MustBlock | Cost$ 2 G | ValidTgts$ Creature | TgtPrompt$ Select target creature | SpellDescription$ Target creature blocks CARDNAME this turn if able.
+A:AB$ MustBlock | Cost$ 2 G | ValidTgts$ Creature | TgtPrompt$ Select target creature | AILogic$ AllowNonLethal | SpellDescription$ Target creature blocks CARDNAME this turn if able.
 T:Mode$ DamageDone | ValidSource$ Card.Self | ValidTarget$ Creature | CombatDamage$ True | TriggerZones$ Battlefield | Execute$ TrigTap | TriggerDescription$ Whenever CARDNAME deals combat damage to a creature, tap that creature and it doesn't untap during its controller's next untap step.
 SVar:TrigTap:DB$ Tap | Defined$ TriggeredTarget | SubAbility$ DBPump
 SVar:DBPump:DB$ Pump | Defined$ TriggeredTarget | KW$ HIDDEN This card doesn't untap during your next untap step. | Permanent$ True | IsCurse$ True

forge-gui/res/cardsfolder/p/profane_procession_tomb_of_the_dusk_rose.txt

@@ -7,14 +7,13 @@ AlternateMode:DoubleFaced
 SVar:Picture:http://www.wizards.com/global/images/magic/general/profane_procession.jpg
 Oracle:{3}{W}{B}: Exile target creature. Then if there are three or more cards exiled with Profane Procession, transform it.
 
-//Not sure if ExiledWithSource and IsRemembered persist through transformation, but for this card, it's absolutely vital that they do.
 ALTERNATE
 
 Name:Tomb of the Dusk Rose
 ManaCost:no cost
 Types:Legendary Land
 A:AB$ Mana | Cost$ T | Produced$ Any | Amount$ 1 | SpellDescription$ Add one mana of any color.
-A:AB$ ChooseCard | Cost$ 2 W B T | Choices$ Creature.IsRemembered+ExiledWithSource | ChoiceZone$ Exile | SubAbility$ DBChangeZone | SpellDescription$ Put a creature card exiled with this permanent onto the battlefield under your control.
+A:AB$ ChooseCard | Cost$ 2 W B T | Choices$ Creature.IsRemembered+ExiledWithSource | ChoiceZone$ Exile | SubAbility$ DBChangeZone | AILogic$ AtLeast1 | Mandatory$ True | SpellDescription$ Put a creature card exiled with this permanent onto the battlefield under your control.
 SVar:DBChangeZone:DB$ ChangeZone | Defined$ ChosenCard | Origin$ Exile | Destination$ Battlefield | ChangeType$ Creature.IsRemembered+ExiledWithSource | ChangeNum$ 1 | GainControl$ True
 SVar:Picture:http://www.wizards.com/global/images/magic/general/tomb_of_the_dusk_rose.jpg
 Oracle:(Transforms from Profane Procession.)\n{T}: Add one mana of any color.\n{2}{W}{B}，{T}: Put a creature card exiled with this permanent onto the battlefield under your control.

forge-gui/res/cardsfolder/r/rampant_elephant.txt

@@ -3,7 +3,5 @@ ManaCost:3 W
 Types:Creature Elephant
 PT:2/2
 A:AB$ MustBlock | Cost$ G | ValidTgts$ Creature | TgtPrompt$ Select target creature | SpellDescription$ Target creature blocks CARDNAME this turn if able.
-AI:RemoveDeck:All
-AI:RemoveDeck:Random
 SVar:Picture:http://www.wizards.com/global/images/magic/general/rampant_elephant.jpg
 Oracle:{G}: Target creature blocks Rampant Elephant this turn if able.

forge-gui/res/cardsfolder/s/sisters_of_stone_death.txt

@@ -4,12 +4,11 @@ Types:Legendary Creature Gorgon
 PT:7/5
 A:AB$ MustBlock | Cost$ G | ValidTgts$ Creature | TgtPrompt$ Select target creature | SpellDescription$ Target creature blocks CARDNAME this turn if able.
 A:AB$ ChangeZone | Cost$ B G | Origin$ Battlefield | Destination$ Exile | ValidTgts$ Creature.blockingSource,Creature.blockedBySource | TgtPrompt$ Select target creature blocking Sisters of Stone Death | RememberTargets$ True | SpellDescription$ Exile target creature blocking or blocked by CARDNAME.
-A:AB$ ChangeZone | Cost$ 2 B | Origin$ Exile | Destination$ Battlefield | ChangeType$ Creature.IsRemembered+ExiledWithSource | Hidden$ True | GainControl$ True | SpellDescription$ Put a creature card exiled with CARDNAME onto the battlefield under your control.
+A:AB$ ChooseCard | Cost$ 2 B | Choices$ Creature.IsRemembered+ExiledWithSource | ChoiceZone$ Exile | AILogic$ AtLeast1 | Mandatory$ True | SubAbility$ DBChangeZone | SpellDescription$ Put a creature card exiled with CARDNAME onto the battlefield under your control.
+SVar:DBChangeZone:DB$ ChangeZone | Defined$ ChosenCard | Origin$ Exile | Destination$ Battlefield | ChangeType$ Creature.IsRemembered+ExiledWithSource | ChangeNum$ 1 | GainControl$ True
 T:Mode$ ChangesZone | Origin$ Exile | Destination$ Any | Static$ True | ValidCard$ Card.IsRemembered+ExiledWithSource | Execute$ DBForget
 SVar:DBForget:DB$ Pump | ForgetImprinted$ TriggeredCard
 T:Mode$ ChangesZone | ValidCard$ Card.Self | Origin$ Battlefield | Destination$ Any | Execute$ DBCleanup | Static$ True | Secondary$ True | TriggerDescription$ Forget all remembered cards.
 SVar:DBCleanup:DB$ Cleanup | ClearRemembered$ True
-AI:RemoveDeck:All
-AI:RemoveDeck:Random
 SVar:Picture:http://www.wizards.com/global/images/magic/general/sisters_of_stone_death.jpg
 Oracle:{G}: Target creature blocks Sisters of Stone Death this turn if able.\n{B}{G}: Exile target creature blocking or blocked by Sisters of Stone Death.\n{2}{B}: Put a creature card exiled with Sisters of Stone Death onto the battlefield under your control.

forge-gui/res/cardsfolder/t/tangle_angler.txt

@@ -3,7 +3,6 @@ ManaCost:3 G
 Types:Creature Horror
 PT:1/5
 K:Infect
-A:AB$ MustBlock | Cost$ G | ValidTgts$ Creature | TgtPrompt$ Select target creature | SpellDescription$ Target creature blocks CARDNAME this turn if able.
+A:AB$ MustBlock | Cost$ G | ValidTgts$ Creature | TgtPrompt$ Select target creature | AILogic$ AllowNonLethal | SpellDescription$ Target creature blocks CARDNAME this turn if able.
-AI:RemoveDeck:All
 SVar:Picture:http://www.wizards.com/global/images/magic/general/tangle_angler.jpg
 Oracle:Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)\n{G}: Target creature blocks Tangle Angler this turn if able.

forge-gui/res/cardsfolder/t/trumpeting_armodon.txt

@@ -3,6 +3,5 @@ ManaCost:3 G
 Types:Creature Elephant
 PT:3/3
 A:AB$ MustBlock | Cost$ 1 G | ValidTgts$ Creature | TgtPrompt$ Select target creature | SpellDescription$ Target creature blocks CARDNAME this turn if able.
-AI:RemoveDeck:All
 SVar:Picture:http://www.wizards.com/global/images/magic/general/trumpeting_armodon.jpg
 Oracle:{1}{G}: Target creature blocks Trumpeting Armodon this turn if able.