Your Project Brief: The One-Page Design Doc

A one-page document capturing the invariants of your game — the few things you refuse to change — while leaving everything else negotiable.

Long docs die because they try to specify decisions that can only be discovered by playing; a one-pager records only the pillars.

To stop you from silently redesigning the game every time you sit down to work on it — it's a promise to your future self.

Check whether a proposed fix violates a pillar. If not, change it freely; if yes, you face a real, conscious decision instead of drifting.

Working title; elevator pitch; player count/age/playtime; core loop; the interesting decision; victory condition; components list; two open questions.

Idea-switching — a half-built game teaches you more than ten pristine concepts.

The single choice players should agonize over, plus its game-theoretic shape (simultaneous-move, prisoner's dilemma, Stag Hunt, auction, congestion game).

They limit scope — e.g., a 25-minute target forbids adding a fourth resource type.

The ordered sequence of what a player physically does on their turn, e.g. draw 2 → play 1 face-down → reveal → resolve → collect income.

A route's payoff is split among all merchants there, so value decreases as more players choose it — no dominant route, mixed strategies emerge.

As genuinely unknown, testable questions, e.g. 'Will players always bid the maximum on turn 1?'

"A game is a series of interesting decisions" — and you can't tell if yours are interesting until they exist on cardboard.