Game Design Document Template for Your AI (One Page)

A game design document for your AI should fit on one page: the idea, the main loop, the rules, the numbers and what is not in the game. Copy the template below, fill it in with your AI, and have it read the page before every change.

Why only one page?

A long design document is written for a team and read by nobody. Yours has one reader that matters, your AI, and it has to take in the whole thing at the start of a session. Every line it reads uses up room for the actual work, and a page you can read in a minute is a page you will keep up to date.

What does the template look like?

# [Game name]
One sentence: [what the player does, and why it is fun]
Who it is for: [one kind of person]
Main loop: [do this, get that, do it again]
How you win and lose: [one line each]
Rules: [three to seven short lines]
Numbers: [starting values, each with a plain name]
Feeling: [three words]
Not in this game: [things you will say no to]
Open questions: [what is not decided yet]

What does a filled-in page look like?

Here it is for Bellhop Panic, an invented game:

# Bellhop Panic
One sentence: You race suitcases up a hotel lift before the guests lose patience.
Who it is for: People with five minutes and a phone.
Main loop: Grab a bag, pick a floor, deliver it, earn a tip, grab the next bag.
How you win and lose: Survive the shift. Three angry guests end it.
Rules: One bag at a time. The lift stops only at floors you choose. A wrong floor costs time.
Numbers: 6 floors, 12 seconds of patience per guest, tips of 5 to 20 coins.
Feeling: Busy, silly, never cruel.
Not in this game: Story, shop, online scores.
Open questions: Should tips buy anything?

Which lines matter most?

Two lines at the bottom do the most work, and they are the easiest to leave out.

"Not in this game" stops the slow growth that kills small projects. When your AI suggests a shop, the page has already said no. When you get the urge at midnight, it says no to you too.

"Open questions" stops your AI from deciding for you. Anything not written down gets filled in with a guess, and you will not notice which parts were guesses. A question on this list is a reminder that the answer is yours.

Two things stay out of this page. A story has its own file, as explained in what a story bible is. And your AI does not need to be told how your files are laid out, because it can look. If your idea is still fuzzy, start with game ideas that fit.

Paste this to your AI

Help me write a one-page design document for my game. Save it as gdd.md.

Interview me, one question at a time, using these headings: One sentence, Who it is for, Main loop, How you win and lose, Rules, Numbers, Feeling, Not in this game, Open questions.

Use my words. If you suggest something, mark it "my suggestion". Where I have no answer, put it under Open questions, and do not decide it for me.

Then draw the Main loop and the win and lose rules as a Mermaid diagram at the top of gdd.md. Walk through it and answer: can every round end, can the player get stuck, does any rule clash with another? Quote the line behind each problem and ask me how to solve it.

From now on, read gdd.md before any change, and build from the diagram. If the game and the page disagree, show me both and ask which is right. If you cannot tell whether they agree, say you do not know. If a request touches "Not in this game", quote that line before you do anything.

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

How to check it worked

• Time it. You should be able to read the page in about a minute.
• Ask a fresh chat what the game is. With only the page, it should describe your game back to you.
• Suggest something from "Not in this game". Ask for a shop. Your AI should quote the line and check with you.
• Ask about an open question. It should say this is not decided yet.
• Follow the drawing. Find the way to losing and the way to winning. If either one is missing, a rule is missing too.