How to write down your game idea

A game idea in your head feels complete. The moment you write it down, the gaps appear, and that is exactly why you should do it early. The goal is not a rulebook. It is a one-page snapshot that lets you (or a friend) understand the game and spot the first questions to answer.

A useful one-pager covers five things. The pitch: one sentence, "a bluffing game where pirates bid on treasure maps that might be fake." The players: how many, and how long a game takes. The core loop: what a turn looks like. The win: how the game ends and who wins. The hook: the one moment or feeling that makes this game different from the games it resembles.

Keep the document alive. After every playtest, update it to match what the game has become, and keep old versions. Reading a three-month-old one-pager is one of the best ways to see how far a design has traveled, and sometimes an abandoned early idea is exactly the fix a later problem needs.