Show HN: A real-time strategy game that AI agents can play

I've liked all the projects that put LLMs into game environments. It's been a weird juxtaposition, though: frontier LLMs can one-shot full coding projects, and those same models struggle to get out of Pokémon Red's Mt. Moon.

Because of this, I wanted to create a game environment that put this generation of frontier LLMs' top skill, coding, on full display.

Ten years ago, a team released a game called Screeps. It was described as an "MMO RTS sandbox for programmers." The Screeps paradigm of writing code and having it executed in a real-time game environment is well suited to LLMs. Drawing on a version of the Screeps open source API, LLM Skirmish pits LLMs head-to-head in a series of 1v1 real-time strategy games.

In my testing I found that Claude Opus 4.5 was the most dominant model, but it showed weakness in round 1 as it was overly focused on its in-game economy. Meanwhile, I probably spent a third of all code on sandbox hardening because GPT 5.2 kept trying to cheat by pre-reading its opponent's strategies.

If there's interest, I'm planning on doing a round of testing with the latest generation of LLMs (Claude 4.6 Opus, GPT 5.3 Codex, etc.).

You can run local matches via CLI. I'm running a hosted match runner with Google Cloud Run that uses isolated-vm. The match playback visualizer is statically served from Cloudflare.

I've created a community ladder that you can submit strategies to via CLI, no auth required. I've found that the CLI plus the skill.md that's available has been enough for AI agents to immediately get started.

Website: https://llmskirmish.com

API docs: https://llmskirmish.com/docs

GitHub: https://github.com/llmskirmish/skirmish

A video of a match: https://www.youtube.com/watch?v=lnBPaZ1qamM

Show HN: A real-time strategy game that AI agents can play
llmskirmish.com

This is actually fun to watch :D

I know visualization is far from the most important goal here, but it really gets me how there's fairly elaborately rendered terrain, and then the units are just unnamed roombas with hard to read status indicators that have no intuitive meaning. Even in the match viewer I have no clue what's going on, there is no overlay or tooltip when you hover or click units either. There is a unit list that tries (and mostly fails) to give you some information, but because units don't have names you have to hover them in the list to have them highlighted in the field (the reverse does not work). Not exactly a spectator sport. Oh, but there is a way to switch from having all units in one sidebar to having one sidebar per player, as if that made a difference.

I find this pretty funny because it seems like a perfect representation of what's easy with today's tools and what isn't

Love the idea though

Great project! It would be interesting to have a meta layer of AIs betting on the player LLMs

Wouldn't it be interesting if the LLMs would write realtime RTS-commands instead of Code? After all it is a RTS game.

This would bring another dimension to it since then quality of tokens would be one dimension (RTS-language: Decision Making) and speed of tokens the other (RTS-language: Actions Per Minute; APM).

Also there are a lot of coding benchmarks, that way it would test something more abstract, similar to AlphaStar https://en.wikipedia.org/wiki/AlphaStar_(software)

You could just use the exposed APIs of OpenAI, Anthropic etc. and let them battle.