Download Civilization -

Win through military conquest, scientific advancement, cultural dominance, or religious conversion.

A completely free, open-source version available on Freeciv.org that runs on Windows, Mac, Linux, and even in web browsers. Download Civilization

If you aren't ready to buy, there are high-quality open-source projects inspired by the series: Win through military conquest

GOG.com offers DRM-free versions, which are great for older titles like Civilization IV . or religious conversion. A completely free