diff --git a/forge-ai/src/main/java/forge/ai/AiCostDecision.java b/forge-ai/src/main/java/forge/ai/AiCostDecision.java
index 2d93d12cf52..1d7179b017f 100644
--- a/forge-ai/src/main/java/forge/ai/AiCostDecision.java
+++ b/forge-ai/src/main/java/forge/ai/AiCostDecision.java
@@ -510,6 +510,15 @@ public class AiCostDecision extends CostDecisionMakerBase {
         Integer c = cost.convertAmount();
         if (c == null) {
             if (ability.getSVar(cost.getAmount()).equals("XChoice")) {
+                if ("SacToReduceCost".equals(ability.getParam("AILogic"))) {
+                    // e.g. Torgaar, Famine Incarnate
+                    // TODO: currently returns an empty list, so the AI doesn't sacrifice anything. Trying to make
+                    // the AI decide on creatures to sac makes the AI sacrifice them, but the cost is not reduced and the
+                    // AI pays the full mana cost anyway (despite sacrificing creatures).
+                    return PaymentDecision.card(new CardCollection());
+                }
+
+                // Other cards are assumed to be flagged RemAIDeck for now
                 return null;
             }
 
diff --git a/forge-ai/src/main/java/forge/ai/ability/LifeSetAi.java b/forge-ai/src/main/java/forge/ai/ability/LifeSetAi.java
index eb849eb92c9..6f4a821870c 100644
--- a/forge-ai/src/main/java/forge/ai/ability/LifeSetAi.java
+++ b/forge-ai/src/main/java/forge/ai/ability/LifeSetAi.java
@@ -124,6 +124,13 @@ public class LifeSetAi extends SpellAbilityAi {
             amount = AbilityUtils.calculateAmount(sa.getHostCard(), amountStr, sa);
         }
 
+        // special cases when amount can't be calculated without targeting first
+        if (amount == 0 && "TargetedPlayer$StartingLife/HalfDown".equals(source.getSVar(amountStr))) {
+            // TODO: this assumes equal starting life for all players, which is not true e.g. for Archenemy
+            amount = ai.getStartingLife() / 2;
+        }
+
+
         if (sourceName.equals("Eternity Vessel")
                 && (opponent.isCardInPlay("Vampire Hexmage") || (source.getCounters(CounterType.CHARGE) == 0))) {
             return false;
@@ -131,8 +138,7 @@ public class LifeSetAi extends SpellAbilityAi {
 
         // If the Target is gaining life, target self.
         // if the Target is modifying how much life is gained, this needs to
-        // be
-        // handled better
+        // be handled better
         final TargetRestrictions tgt = sa.getTargetRestrictions();
         if (tgt != null) {
             sa.resetTargets();
diff --git a/forge-gui/res/cardsfolder/t/torgaar_famine_incarnate.txt b/forge-gui/res/cardsfolder/t/torgaar_famine_incarnate.txt
index f87381c9654..78d418b99ee 100644
--- a/forge-gui/res/cardsfolder/t/torgaar_famine_incarnate.txt
+++ b/forge-gui/res/cardsfolder/t/torgaar_famine_incarnate.txt
@@ -2,12 +2,11 @@ Name:Torgaar, Famine Incarnate
 ManaCost:6 B B 
 Types:Legendary Creature Avatar 
 PT:7/6
-A:SP$ PermanentCreature | Cost$ 6 B B Sac<X/Creature> | Announce$ X
-S:Mode$ ReduceCost | ValidCard$ Card.Self | Type$ Spell | Amount$ Y | EffectZone$ All | Description$ As an additional cost to cast this spell, you may sacrifice any number of creatures. This spell costs {2} less to cast for each creature sacrificed as an additional cost. 
+A:SP$ PermanentCreature | Cost$ 6 B B Sac<X/Creature> | Announce$ X | References$ X,Y | AILogic$ SacToReduceCost
+S:Mode$ ReduceCost | ValidCard$ Card.Self | Type$ Spell | Amount$ Y | EffectZone$ All | References$ Y | Description$ As an additional cost to cast this spell, you may sacrifice any number of creatures. This spell costs {2} less to cast for each creature sacrificed as an additional cost.
 SVar:X:XChoice
 SVar:Y:SVar$X/Times.2
 T:Mode$ ChangesZone | Origin$ Any | Destination$ Battlefield | ValidCard$ Card.Self | Execute$ TrigSetLife | TriggerDescription$ When CARDNAME enters the battlefield, up to one target player’s life total becomes half their starting life total, rounded down.
-SVar:TrigSetLife:DB$ SetLife | ValidTgts$ Player | LifeAmount$ HalfLife | TargetMin$ 0 | TargetMax$ 1
+SVar:TrigSetLife:DB$ SetLife | ValidTgts$ Player | LifeAmount$ HalfLife | TargetMin$ 0 | TargetMax$ 1 | References$ HalfLife
 SVar:HalfLife:TargetedPlayer$StartingLife/HalfDown
-SVar:RemAIDeck:True
 Oracle:As an additional cost to cast this spell, you may sacrifice any number of creatures. This spell costs {2} less to cast for each creature sacrificed as an additional cost.\nWhen Torgaar, Famine Incarnate enters the battlefield, up to one target player’s life total becomes half their starting life total, rounded down.
\ No newline at end of file