Roam

Card game ideas built on one sharp rule

A card game idea is only as good as its core rule: what a card does when you play it, and what you give up to play it. Balatro (2024) and Slay the Spire (2019) both came from tiny teams with one sharp rule. Here are nine digital card game ideas, each with its rule and a sentence to type into Roam.

9 card game ideas and their core rule

Tips for a first card game

Start with fewer than 30 cards. Give each card one job, and make a few cards better together than apart. That combo moment is the fun.

Test on paper first if you can: write cards on index cards and play three rounds before you build anything. If players keep picking the same card, it is too strong. If no one ever plays a card, cut it.

Balatro shows how far one rule goes: you play poker hands, and jokers change how those hands score. No new card types, just new ways to bend the old ones.

Card games on Roam

CARDBOUND is a card-collecting adventure: build a deck, win the Grand Duel Cup. BRAINROT ARENA is a card tower battle with meme cards. Crystal Clash is a card-tower arena. Crypt Deck is a roguelike deckbuilder with a boss on every floor. Mate the Machine is a chess roguelike card battler. Pumpkins Pay Out is a farm slot roguelite: plant the cards, spin the pumpkins, pay the tax.

Play it on Roam

Make your card game with Roam

Write the core rule and what the cards are in one sentence, and play it on your iPhone. Ask for a new card when the deck gets stale.

Try: "heist card game, draw crew cards, match their skills to each door, alarms if I fail, reach the vault in 10 turns"

Questions people ask

What is a deckbuilder?

A game where you start with a small, weak deck and add cards as you play. Slay the Spire made the format popular as a roguelike.

How does Balatro work?

You play poker hands to score chips, and jokers change how hands score. Beat each round's target to move on.

How many cards should a first card game have?

Twenty to thirty is enough to test. Add more once players have learned the first set.

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