Command and Conquer Style RTS Called Battle Drones

Simon Willison built Battle Drones, a Command & Conquer-style real-time strategy game that runs in the browser, mainly using Claude Opus 5.5, and published it on October 20, 2026. Battle Drones supports human-vs-AI and human-vs-human play, plus LLM-vs-LLM matches that pause the game every 5 seconds so models such as Haiku 5.5 and GPT-6 Luna can queue commands, and Claude generated all of the Three.js 3D models. Willison added online multiplayer through a WebSockets relay server hosted on Fly.io after the original device-to-device audio-link multiplayer produced a high-pitched noise that caused headaches.

Simon Willison on X: "I built a Command & Conquer style RTS called Battle Drones, mainly using Claude Opus 5.5, which runs in the browser and includes device-to-device multiplayer over an audio link https://t.co/OUGfRDk7DU" I built a Command & Conquer style RTS called Battle Drones, mainly using Claude Opus 5.5, which runs in the browser and includes device-to-device multiplayer over an audio link simonwillison.net/2026/Oct/20/ba… I built a Command & Conquer style RTS called Battle Drones, mainly using Claude Opus 5.5, which runs in the browser and includes device-to-device multiplayer over an audio link simonwillison.net/2026/Oct/20/ba… In addition to human-vs-in-game-AI and human-vs-human it supports two LLMs playing against each other That works by pausing the game every 5s for them to think about the game state and queue up commands Here's a replay link for Haiku 5.5 vs GPT-6 Luna: simonw.github.io/battledrones/v… Claude generated all of the 3D models in Three.js - here's a model explorer that lists them all plus their animation states. My favorite is the giant "Goliath" stomping mech simonw.github.io/battledrones/m… Warning if you're going to try this: the audio multiplayer plays a high pitched noise throughout the game - annoying at best, and at worst might give you an actual headache Natalie: "why do my teeth hurt?" OK, that headache bug was really bad It inspired me to add proper online multiplayer to Battle Drones via a tiny @flydotio hosted WebSockets relay server - now you can start an online game and send a link to a friend so they can join you simonwillison.net/2026/Oct/20/ba… Looks really good. In the years of CDs I would definitely buy one with these screenshots. How many Claude Code Max 200 subs would you need to code this in a week?