New AI Benchmark Tests Long-Term Thinking in Civilization V

A group of researchers has built a new benchmark called CivBench to test how well large language models (LLMs) can play the complex strategy game Civilization V. In the game, you guide a civilization through hundreds of turns of expansion, science, diplomacy, and war. The key challenge is that decisions made early on might not show their consequences until 50 or 100 turns later. This makes it a great way to measure an AI's ability to plan for the long term, something standard tests often miss.

The experiment is carefully controlled. Each AI model plays the same three starting scenarios, controlling two of the eight civilizations while the rest use the game's standard AI. The LLM only sets high-level strategy; the game's built-in AI handles the details. So far, GLM-5.3 has outperformed Opus-5.5, and the smaller Qwen-3.8-27B has held its own surprisingly well. The researchers are still testing other models like GPT-6.1-Sol and GPT-6-Astra.

What's exciting is that you can try this yourself. The project, called Vox Deorum, is open source and has an installer. If you own Civilization V (currently on sale for $7.49 on Steam), you can play against AI-powered civilizations, watch AI-vs-AI games, or even team up with an AI. You can run it with local models or use existing subscriptions like Claude or Codex. The cost is low—about $0.50 per player per game using API access.

The researchers have also published papers on their methodology and on whether AI models would authorize nuclear strikes. This benchmark not only pushes AI capabilities but also gives everyday people a fun way to interact with cutting-edge AI. It shows how AI is getting better at long-term planning, which could eventually help with real-world tasks like project management or strategic decision-making.