diff --git a/packages/web/src/App.svelte b/packages/web/src/App.svelte
index 2aba538..da90097 100644
--- a/packages/web/src/App.svelte
+++ b/packages/web/src/App.svelte
@@ -912,10 +912,18 @@
       return;
     }
     const me = view.players.find((p) => p.id === view.you)!;
+    // "Spells cast at the slime get stuck there": an attack tapped onto a
+    // slime waits in the gel for whoever enters.
+    if (selectedCard && view.squareContents[cellKey(cell)]?.kind === "slime" &&
+        cardDef(selectedCard.cardId).cardType === "attack") {
+      dispatch(withMods({ type: "cast", instanceId: selectedCard.instanceId, target: { kind: "cell", cell } }));
+      clearSelection();
+      return;
+    }
     // A card in hand is aimed, not walked with: a tap on a bare square
     // while holding one is a miss, never a stride into whatever is there.
     if (selectedCard) {
-      net.error = `${cardDef(selectedCard.cardId).name} is aimed by tapping a wizard or creature — put the card down to walk`;
+      net.error = `${cardDef(selectedCard.cardId).name} is aimed by tapping a wizard, a creature, or a slime — put the card down to walk`;
       setTimeout(() => { if (net.error?.startsWith(cardDef(selectedCard!.cardId).name)) net.error = null; }, 5000);
       return;
     }