I had GPT-6 Astra build a League of Legends clone. I gave it one prompt, closed the laptop, and came back to a working game — real champions, real abilities, combat that felt right. The prompt is below, word for word.
The prompt matters. The setup matters more. Read that part first.
The setup — read this first
- Open Codex. It lives inside ChatGPT. This is a build job, not a chat, so don’t paste this into a normal conversation.
- Set the model to GPT-6 Astra.
- Set the effort level to Max (see below).
- Paste the prompt exactly as written. Don’t shorten it, don’t “improve” it.
- Let it run. This is an overnight job — start it, walk away, check in the morning.
High vs Max. High will get you a playable build. Max is what built mine — it gives the model more room to plan, build and test before it hands anything back, and on a project like this the difference lands exactly where it matters: the combat feel, the UI polish, the things that separate “a real game” from “a demo”. If you’re only going to run it once, run it on Max.
đź“‹ The prompt
Copy everything in the box and paste it as your first message.
Create a high-fidelity, fully playable single-player recreation of League of Legends that prioritizes authenticity above all else.
Replicate Summoner’s Rift as closely as possible in layout, scale, and visual language, with comparable 3D graphics, lighting, and environmental detail. Include the complete core systems: minions, towers, inhibitors, nexus, jungle camps and monsters, vision, leveling, gold, item shop, and win conditions.
Populate the game with the real champions Garen, Ashe, Ahri, Lux, and Lee Sin, complete with accurate ability kits, passive effects, base stats, and progressive scaling. Support 5v5 matches against competent AI bots.
The interface must be a native, polished game UI that closely mirrors the look, feel, hierarchy, and responsiveness of the official League of Legends client — no HTML overlays or web-based elements. Prioritize fluid controls, clear visual feedback, and an overall experience that feels like the real game rather than a simplified prototype.
Build it as a complete, immediately playable prototype that demonstrates deep mechanical and aesthetic fidelity.
Once it’s done
- Tell it to launch the game and play a match. Judge it from the screen, not the code.
- Something off? Say it in one plain sentence — “minions aren’t pushing lanes”, “Ahri’s Q doesn’t come back” — and let it fix it. You don’t need to know why it broke.
- Want a sixth champion, a different map, your own rules? Ask. You’re the game director now.