Write the prompt around a playable rule
The example uses three effects with different roles and a visible opponent intent. It helps test whether players understand attack, defense and setup without reading a large deck. Ask for energy costs and card outcomes on each card face. Keep health and intent visible in the same area so a player can weigh a risky strike against a defensive turn.
Original concept prompt: “Make a turn-based duel with a hand of three cards and three energy per turn. Strike deals two damage, Guard blocks the next attack, and Focus restores one energy next turn. Show the opponent’s intended move before the player acts; alternate turns until one health bar reaches zero.” This is a recipe for an idea, not a claim that this exact game is already playable.
Play, observe and refine one thing at a time
Play the duel using each card at least once and check that the effect matches the displayed text. See whether Guard blocks exactly the next attack and whether Focus pays back at the stated time. If a choice is always best, vary the opponent’s announced intent in a second test. If the interface hides the turn order, add a clear “your turn” and “opponent turn” cue.
Add a single new card only when the original three already create distinct decisions. A healing card, for example, can make timing matter if health is limited. Avoid a deck-building system until the duel itself is clear. Compare one cautious run and one aggressive run; if they feel identical, revise the effect timing or resource trade-off.
Do not use card rarity or elaborate artwork to disguise effects that play the same way. Keep text short and rules consistent. If players lose without understanding the opponent’s move, reveal intent earlier or explain damage and blocking before the first decision.
Playable reference for this prompt: Stone Keep. Build and upgrade walls, archer towers, cannons and gold mines around your island keep, then alternate rounds: hurl catapult stones at landing raiders to defend it, and drop knights on the shore to raid enemy camps for stars and gold. Use this example to compare the proposed rules with a game you can try now. For your version, use this check: What needs to be explicit about card effects?
Questions about card battle game prompt
What needs to be explicit about card effects?
Define when damage, blocking and next-turn energy take effect. Test combinations and repeated clicks so a card cannot resolve twice or leave ambiguous state.
Why show the opponent intention?
It gives the player information for choosing between attack and defense. Check that the actual enemy action matches the displayed intention for that turn.