📄 The one rule
Everything goes in one file. No separate CSS files. No JavaScript imports from your own server. No build step. One .html file that a browser can open directly — or that you can paste into a text box and publish instantly.
This is the constraint that makes everything else possible. An AI can write one complete file in a single response. You can read it, copy it, fork it, share it. There is nothing hidden. The hood is always up.
External fonts and libraries from CDNs are fine — those are already on the internet. Everything else: inline it.
🗣️ How to write good instructions
The most common mistake is describing how you feel about something rather than what you actually see. AIs build what they're told. The more precise the instruction, the closer the result.
"Make it look better and add some games stuff"
"Change the background to dark navy. Add a score counter in the top right corner that starts at 0 and increases by 10 each time the player clicks the target."
"The timer is broken, fix it"
"The timer counts down from 30 but stops at 1 instead of 0. When it reaches 0 it should show a Game Over message and stop the player from moving."
🚀 Starting prompts — copy and use
These are starting points. Change the words in brackets to match what you want to build.
A simple game:
Build a single self-contained HTML file for a [type of game] game. Rules: [describe the rules in plain English] Controls: [keyboard / mouse / touch] Visual style: [e.g. bright colours, dark background, pixel art feel] Include: a score counter, a start screen, and a game over screen. No external files. Everything inline in one HTML file.
A tool or utility:
Build a single self-contained HTML file for a [tool name]. What it does: [describe in plain English what the user can do with it] Inputs: [what the user types or clicks] Outputs: [what the tool shows or calculates] Style: clean, readable, works on mobile. No external files. Everything inline in one HTML file.
A page or invitation:
Build a single self-contained HTML page for [what it is — e.g. a birthday invitation / event page / personal homepage]. Content to include: [list what should be on it] Colours: [describe or name them] Font style: [e.g. friendly and rounded / clean and minimal / bold and dramatic] No external files. Everything inline in one HTML file.
Forking something that already exists:
Here is an existing HTML file: [paste the full HTML] Make the following changes only. Do not change anything else: 1. [First change, described precisely] 2. [Second change, described precisely] Return the complete updated file.
🔁 The revision loop
Almost nothing arrives perfect on the first attempt. That is not a failure — it is the process. Here is how to get from a first draft to something you're happy with:
- 1Run the file in a browser. Look at everything. Write down exactly what is wrong — not "it looks off" but "the score counter overlaps the timer on mobile screens narrower than 400px".
- 2Send all the fixes in one message. List them clearly. Batching saves time and reduces the chance of new changes breaking old ones.
- 3Paste the full returned file back into your browser. Repeat.
- 4When you're happy, publish it. The file is the finished thing.
✅ Before you publish — quick checklist
Does your file...
📖 Want to go deeper?
The Metatellicomunicon is the full BTH ritual book — sixteen schools of game-making, with summoning rituals, common bugs, and chronicles from the field. If this guide got you started, the book takes you further.
Built something?
Publish it to the BTH Workshop. It gets a live URL instantly, stays forkable forever, and both you and your AI get the credit.
⚡ Publish your file →The lineage goes with it. That is the whole point.