What Can I Do with ioquake3?

ioquake3 is a free and open-source first person shooter engine built on the Quake 3: Arena and Quake 3: Team Arena source code. You can use it to play Quake 3: Arena, Quake 3: Team Arena, and community-made mods; to run your own game server; or to build your own game from its source code. You do not necessarily need to own Quake 3 to get started, since you can also play games that other teams have built with ioquake3.

Play Quake 3 and its mods

The most direct use is playing the games the engine was built from. According to the project, ioquake3 lets you play:

• Quake 3: Arena — the base game
• Quake 3: Team Arena — the official expansion
• Mods made by the community for either of those games

If you are new to this, the project points players to its Player's Guide for instructions and help getting a game running.

Do you need the original Quake 3?

Not always. The site notes that if you don't already have Quake 3, you can play a game that other teams have made using ioquake3. That means the engine itself is a starting point, and there are standalone projects built on it that don't require the original commercial game.

If you do want the original titles, the site links to a page for buying Quake 3: Arena & Team Arena. Note that ioquake3 is a separate community project — it is not part of, or sponsored by, id software, Bethesda, or Microsoft, even though id software released the original source code.

Run your own game server

Beyond playing, you can host games for others. The project provides a SysAdmin Guide specifically for getting started running your own game server. This is the path to take if you want to manage matches, configure settings, or keep a persistent server online for a community.

Make your own game

Because ioquake3 is open source under the GPL version 2, you can build on it. The source code is available in git on GitHub, and the project explicitly invites you to "make your own game from our source code."

This is a realistic option if you want an FPS engine foundation rather than starting from scratch. The engine has been maintained and improved since id software first released the code under the GPL on August 20, 2005, with bug fixes and new features added over the years.

A concrete example

Suppose you want to prototype a small arena shooter. Instead of writing rendering, networking, and input handling yourself, you could start from the ioquake3 codebase, strip it down to what you need, and focus on your own weapons, maps, and rules. The project even highlights community events like game jams as a reason to prepare — for instance, the 2025 7DFPS Game Jam (December 5th–14th) was announced on the site as a moment to start building an FPS with ioquake3.

Get involved or give back

If you want to contribute rather than just use the engine, the project welcomes help. The site lists ways to get involved and suggests following the project on Mastodon and Blue Sky to stay in touch. Contributions come from volunteers, with resources from Discourse.org, icculus.org, and Nuclear Monster.

Quick reference

Downloads

ioquake3 offers downloads for Windows, macOS, and Linux, with more downloads available on the site's download page. Start there if you want to play or test the engine before deciding whether to build on it.