Make a Card Game With AI: Start With 12 Cards

Make your card game on paper first: twelve scraps with writing on them, played with a friend, will teach you more than any code. Then have your AI build those twelve cards from a few simple effects stored in one table, so that a new card is a new row and not new programming.

Why are cards so much harder than they look?

Because every card is a tiny rule that changes the other rules. Look at the sums. Twelve cards can meet each other in 66 different pairs. A hundred cards can meet in 4,950. Each of those pairs is a chance for two cards to disagree about what happens next.

Say your game is about two mountain guides racing to a summit. Rope moves you three steps. Fog makes your rival skip a turn. Then you add Avalanche, which sends everyone back two steps, and Anchor, which says you can never move backwards. What happens when they meet? If your AI has written Anchor as a special case, the answer is whatever happens to come first in the code. Nobody decided it.

How do you keep the cards under control?

Build each card from a few building blocks. For the guides, four will do: move, draw, discard, skip. A card is then just a row:

Card	Effect
Rope	move yourself +3
Fog	rival skips a turn
Avalanche	move everyone -2
Second Wind	draw 2, discard 1

Writing Anchor now forces a decision about one rule, once, for every card. You will also want a plain rule for which effect goes first. Say that out loud before your AI has to guess.

One detail worth naming: ask for a Fisher-Yates shuffle. Wikipedia describes it as giving every order an equal chance, and warns that the shortcut of sorting a deck in random order is very likely to give uneven results. Players will not know why the deck feels odd, and they will notice.

Which order works?

1. Twelve paper cards, played at a table with someone else, until you have changed the rules twice.
2. The card table, with your four building blocks.
3. Shuffle, draw, hand, discard pile, and a reshuffle when the deck runs out.
4. One full turn, and a way to win.
5. A computer rival that follows one plain rule, such as "play the card that moves me furthest". A turn-based structure keeps it simple.
6. New cards, three at a time.

What kills card game projects?

The hundred-card dream. Your AI will happily invent a hundred cards this afternoon, and each one will look clever on its own. Nobody will ever have played them. Keep to twelve until those twelve are fun, then add three, play, and add three more.

Paste this to your AI

Help me build a two-player card game with a simple computer rival. Ask me up to five questions about my rules, then stop and wait.

Then draw one turn as a state machine in a Mermaid diagram: draw, play, apply the card, discard, look for a win, other player's turn, deck empty so reshuffle. Show me what happens if a card ends the game halfway through its effect. Build only after that.

Twelve cards, kept in one table, each made from a few building blocks such as move, draw, discard and skip. Use a Fisher-Yates shuffle.

Then give me the exact odds of each card in an opening hand, and simulate many games between two random players. Show who won how often and which cards were never worth playing. With no numbers behind it you do not know if it is fair, so say that.

Or skip this and connect the MCP: your AI then finds all of this by itself.Connect the MCP

How to check it worked

• Deal ten opening hands. The same cards should not keep turning up first.
• Empty the deck. Play until nothing is left. The game should reshuffle, or end as your rules say.
• Find the card you never play. Cut it or change it.
• Play two cards that argue. Try your Avalanche and Anchor pair. The result should be the one you decided.
• Add a card. Add one row to the table. It should work with no other change.