Free rules / Game jam

Game Jam Rules for AI Coding (free)

An AI coding tool can build a lot in a weekend, and that's the problem: it happily adds a second mechanic at hour 40 and breaks the build you were about to submit. These 12 rules keep it on one mechanic, keep the game playable, freeze features at the halfway mark and make you export early. Engine-neutral, free, no signup.

Works in: a Cursor rule, CLAUDE.md, AGENTS.md, or ChatGPT/Claude custom instructions · Engines: Phaser, Godot, Unity or anything else · Updated Oct 23, 2026

How to use it

1. Before the jam starts, copy the rules below or download game-jam-rules.md.
2. Paste them into your AI tool's rules file or system prompt.
3. When the theme drops, give the AI the jam's length, theme, engine, and the jam page's rules on assets and AI use. Rule 1 makes it repeat them back, so check that it got them right.
4. Keep ASSETS.md up to date as you go. It becomes your credits and AI-use note at submission time.

Upcoming jams that allow AI tools

Most jams ban AI. Many popular itch.io jams forbid AI-generated code, art or music outright. If yours does, don't use this file to generate content. Read the jam page before you start.

• All Tools Allowed #3 (Critics Arcade), Oct 23-26, 2026 (72 h, closes Oct 26 17:00 UTC). The jam page says: “Any tool, no apologies. Generative AI, coding agents (Claude Code, Cursor, Copilot), asset packs, any engine.” You must list the tools you used on your submission page; no disclosure means no entry.
• Slapjam #2, Oct 29-31, 2026 (48 h, closes Oct 31 15:00 UTC). The jam page says: “Use AI tools as part of making your game.” Mobile-portrait browser games (aim for 720×1280), touch controls, playable in the browser on itch.io.

Checked on each jam's own page on Oct 23, 2026. We take jams off this list after submissions close. Rules can change, so the jam page always wins.

The rules file

# Rules for AI coding during a game jam

> Paste this into your AI tool's rules (a Cursor rule, CLAUDE.md, AGENTS.md, or a chat's custom instructions) before the jam starts. Then tell it the jam's length, theme, engine and the jam's own rules.

1. Before writing any code, restate the jam rules I gave you: length, theme, engine limits, team size, and whether pre-made assets and AI-generated code, art, music or voice are allowed. If I haven't given them, ask. Never assume AI-made content is allowed; many jams restrict it.
2. One core mechanic. In the first hour, help me write a 3-line design: what the player does, how they win, how they lose. Don't add a second mechanic until the first one is fun and finished.
3. Keep the game playable at all times. Every change must leave a build that starts and runs. After each feature, tell me how to test it in under a minute.
4. Small diffs. One feature per change, and no rewrites of systems that already work. If a change would touch more than 3 files, stop and explain the plan first.
5. Placeholder art and sound first (colored shapes, simple beeps) until the core loop works. Log every asset I didn't make in ASSETS.md: where it came from, its license, and whether it was AI-generated.
6. Feature freeze at the halfway mark. After that, only bug fixes, game feel (sound, screen shake, particles), a title screen and on-screen controls.
7. Export early: make the first real build (for example a web build) in the first quarter of the jam, then again every few hours, and test the exported build, not just the editor.
8. For a browser build on itch.io: upload a ZIP with index.html in it, use relative paths for every asset, and match file name case exactly (file names are case sensitive there).
9. No accounts, servers, leaderboards or online features unless the jam is about them. Save data locally.
10. A new player should understand the game in 10 seconds: show the controls on screen and keep the first level short.
11. In the last hours, help me write the submission page: a one-line pitch, controls, credits for every asset in ASSETS.md, the tools used, and an honest note on AI use if the jam asks for one.
12. Before I submit, list anything unfinished, untested or unverified so I can decide what to cut.

Every jam sets its own rules, so the jam page always wins over this file. Find jams on itch.io; for browser builds, see itch.io's HTML5 upload guide (ZIP with an index.html, relative paths, case-sensitive file names).

Want a head start before the next jam? The Game Prototype Cartridge ($29) is a playable Phaser 4 starter with tests, a one-command web build and agent rules for game code.

After the jam (sister projects): check your gameplay clip's safe zones free on ClipLint · turn your jam game into a Steam page with WishlistForge