Eight fine Quake III Arena mods were published on Desura. Most of them (six!) are total conversions.
Total conversions: Q3 Rally, Urban Terror, Bid for Power, Combat, True Combat, Navy SEALs: Covert Operations
Partial conversions extending the core gameplay: David Hunter and Excessive +
You can play these mods via retail ("play") or Steam ("play through Steam") if you have a Steam copy of Quake III Arena. Also note that Quake III Arena and consequently its mods are mostly multiplayer-oriented, so you'll probably have to grab your buddies to play these mods (as zero to few servers are up at the moment).
A car driving and car combat modification.
"Where Quake meets reality" is the motto the developers of Urban Terror have adopted. While many mods these days tend to focus on realistic game play, Urban Terror takes a "fun over realism" approach to the FPS arena by keeping the Q3 speed and physics.
Bid For Power is a total conversion for Quake III that plays nothing like the original game. Players take control of Ki-powered superheros and battle it out in a mostly aerial fight. The game is highlighted by the work of a great art team and an original style, and the gameplay is extremely fast paced.
David Hunter is an unwitting collaboration of some of the very best 3rd party productions for Quake III Team Arena. Packaged into a single megalithic title, it is combined with the awesomely modified David Hunter game play, creating a modification for pure thrill factor, David Hunter features an entirely new game style, based around the player set-up skirmish. Battle over a wide array of maps built in an equally wide range of styles, sizes and scales. The extremely fast paced adrenaline pumping game play can provide some extremely tense moments, and by comparison, most 1st person shoot ‘em up titles cannot compete with the pure intense game play driven action provided by David Hunter. Only in the David Hunter universe will you get to fight with such ferocity against an unforgiving foe! Solid walls of lead are unleashed upon unsuspecting foes with an unnatural fury, exhilarating bolts of energy sear across beautifully drawn arenas and a great many corpses line the battlefields.
Got tired of standard CPMA/QuakeLive ? Excessive Plus is for you, the fastest, most explosive 3D Action/Shooter (FPS) active mod in the world. It works with Quake III, IoQuake3, OpenArena and Xreal. What's possible on Quake3 excessiveplus ? Shortly, you can do anything with excessiveplus ! So join it, and enjoy it ;] "E+ is modification where all weapons and movement, are super-powerful and in every way excessive."
Inspired by a subgame in the classic Atari title of the same name, you are a crack tank commander pitted against tank drivers like yourself in a variety of malevolently-designed arenas, forced to fight for pie, cake, and your very survival (insert maniacal laughter). You fight from an overhead perspective (looking down at your tank and the rest of the arena) against bots (artificially-intelligent computer-generated buzzword buzzword opponents) or against other humans online with your treaded vehicles machine gun and mortar cannon. Support gametypes include everything included in base Quake...
True Combat is an action packed realism mod where big jumps, fancy strafing and fantasy weapons are no where to be seen. Expect hard fought team-based objective battles where staying alive is only the first challenge you will face.
Navy SEALs: Covert Operations is a realism total conversion mod for ID Software's Quake3 engine. NS:CO pits players in realistic combat missions such as:
- Retrieve Information in a suitcase and return it to a capture point
- Defend Fortified Area's from Capture
- Assassinate VIP Player (distinct model for VIP)
- Capture Specific Points on the map for your team to win.
Navy Seals has one of the most realistic damage effects you will ever see in a Mod. You won't see anyone taking one-hundred bullets and surviving here. It's all based on reality and how bullets really effect someone when hit by them. NS:CO Feature Highlights Weapons, Weapon Handling & Equipment * 22 scale real worked weapons * sophisticated weapon attachment system * scopes, flashlights, bayonettes, laser sights, silencer etc. * 5L-SD, sophisticated location specific damage system * projectile code system - realistic per projectile ballistic physics and more!
Mods install to the main game directory. You can also set your own mod launch commands on Desura, a short User Launch Options tutorial is here.