When id software released the Quake III engine under the GPL in 2005 the way to a totally free game was far from complete. As with the earlier versions the data files (graphics, sounds and level descriptions) remained proprietary. The OpenArena project created free replacements for the data files and released it together with the engine as a full-featured game.
Some things that have been said about Quake III Arena (Q3A) apply to OpenArena as well. So instead of large levels full of monsters as in earlier first-person shooter games like Doom the player faces only a few human or computer-controlled opponents (the latter being called bots) in relatively small-sized levels. When a character dies, it immediately returns to the game. The game offers four playing modes:
OpenArena is partly compatible with Q3A. You can use any map and most mods (some textures may be missing) available on the net, and many of them are even free as in speech. However, it is not possible to play against Q3A users in a multiplayer game.
A bot firing rockets
The graphics of OpenArena are quite impressive, especially the dynamical light effects made by weapon fire are an eye-catcher. Some textures look a bit boring. However, since OpenArena is a high-speed arcade action shooter you hardly have time to notice it. Another advantage is the game's relatively modest hardware hunger — any not too out-dated machine with a 3D graphics accelerator will do the job.
The weapons arsenal contains the usual suspects, ranging from a machine gun to a rocket launcher. The weapon system is fairly balanced, with no "super-weapon" that rules all others.
OpenArena features pretty intelligent bots with adjustable strengths. They show tactical behavior like switching weapons when appropriate or retreating before running out of health.
Long-term fun is some problem, however. Unless you install additional ones there are only seven maps to play and without any special rules like in Nexuiz's campaign mode, hunting bots gets a bit dull after some time.
Nevertheless, OpenArena is a good choice if you are interested in quick fast-paced action. Especially in multiplayer mode fun is guaranteed.