# Game Dev: five rules for building a small game with coding agents, and a five-check script (free sample)

> From the Game Dev bundle: five rules for a small game built with coding agents (pin the engine version in the project and the agent's rules, a first test before each milestone, done means played by an agent and a person, a license for every asset, uploads wait for the owner's yes), and a read-only script that checks one small file for them.

- URL: https://paperchasewebb.ai/bots/marketplace/items/game-dev-five-rules-for-building-a-small-game-with-coding-agents-free-sample/
- Type: Prompt pack
- Category: Games
- By: PaperChaseWebb
- Works with: Claude Code, Codex, Grok Bot, Hermes (named in the listing); Plain .md plus one Python 3 script, standard library only; one prompt for all four harnesses
- Price: Free USD
- Difficulty: Beginner
- Setup time: 5 min
- Time to result: About five minutes to a first result
- Format: Markdown (.md) file, game-dev-five-rules-for-building-a-small-game-with-coding-agents-free-sample.md
- Version: 1.0, updated 2026-10-29
- License: Personal and commercial use.

## What you end up with

In a few minutes you can see which build decisions are missing before an agent writes code for the wrong engine version or uploads a build on its own.

## What you get

- Five game build rules
- game_mini.py: five read-only checks on one game.json
- One prompt for all four harnesses
- Worked example: 5 findings, then 0

## Who it is for

Anyone making a small game with coding agents who wants a quick check of the basics first.

## Tools needed

- Grok Bot, Claude Code, Codex or Hermes: the agents that write the code, make the assets and export the builds; each reads the skill file, AGENTS.md snippet or rules block and checks game.py gate before acting
- Python 3: runs game.py (init, hash, gate, request, owner approval, verify, done) and the fifteen-check checker; standard library only, no network
- You need: Python 3.9 or newer
- You need: Any of Grok Bot, Claude Code, Codex or Hermes

Cost to run: Free.

## Sample prompt: Pin the engine (Grok Bot, Claude Code, Codex, Hermes)

```
Read the project file and tell me the engine version it says. Then read game.json.
If the version differs from engine_version or rules_version, stop and show me all three. Do not change any of them yourself.
```

The rules and the script are in the file.

## Free preview of game-dev-five-rules-for-building-a-small-game-with-coding-agents-free-sample.md

````markdown
# Game Dev: five rules for building a small game with coding agents, and a five-check script (free sample)

Version 1.0, 2026-10-29. By PaperChaseWebb. For solo developers and small teams making a jam game or prototype with Grok Bot, Claude Code, Codex or Hermes in Godot, Unity, Unreal or a web engine. One Markdown file and one Python 3 script, standard library only. The script was tested on its worked example (5 findings, then 0) and on a missing file (exit 2). It was not run inside any agent harness or next to a real engine project.

Most trouble with agents on a small game comes from a few missing decisions. The agent's rules say one engine version and the project says another. A feature is built before anyone wrote how to test it. A milestone is called done because the agent said so, and nobody played it. A sound file goes into the build with no license on file. The agent uploads a build on its own. This sample gives you the five rules that cover those, and a script that checks them on one small file.

## Install in one line

Save this page as FREE-SAMPLE.md, then:

```
python3 -c "import re;t=open('FREE-SAMPLE.md').read();open('game_mini.py','w').write(re.search(r'~~~python\n(.*?)~~~',t,re.S).group(1))"
python3 game_mini.py game.json
```

## Five game build rules

1. **Pin the engine version, in the project and in the agent's rules.** The same number in both, written as numbers, never "latest". If they differ, the agent stops and asks.
2. **Every milestone has a first te
````

## Test record

- Date: Oct 29, 2026
- What was run: game_mini.py on the worked example, a fixed file, a missing file, and the copy taken from the sample file.
- Result: 5 findings, then 0; exit 2 on a missing file; the copy behaved the same.
- Not run: The prompt inside a harness or next to a real engine project.

Copied from this item's dated test notes. What was not run stays in.

## Worth knowing

- The sample checks one file against five rules. The full Game Build Runbook, gate, request approvals by hash, asset ledger, build budgets and the fifteen checks are in the full bundle.
- On 2026-10-29 game_mini.py gave 5 findings on the worked example, then 0 on the fixed file, and exited 2 on a missing file; the copy extracted from the sample file behaved the same. The prompt was not run inside a harness or next to a real engine project.

## Questions

**Does it send anything anywhere?** No. It reads one file and opens no network connection.

**What is in the full bundle?** The Game Build Runbook with fifteen checks and owner approval tied to each request's hash, plus Game Jam Kit, Unreal from Codex, Game Assets as Code and Engine Agent Kits in full. $69, against $111 for the four bought separately.

## How to get it

Free sample. Download it directly at https://paperchasewebb.ai/bots/marketplace/items/game-dev-five-rules-for-building-a-small-game-with-coding-agents-free-sample/, no signup.

Seller: PaperChaseWebb Inc., mgmt@paperchasewebb.com