OpenArena is a PC First-Person Shooter for Windows, UNIX and macOS. The game is an open-source clone of Quake III: Arena, with the vanilla gameplay kept intact: score frags to win the game using a balanced set of weapons each designed for different situations. Like Id's game, the style of play is very fast and requires skill to be played successfully online.
The gamemodes included are Deathmatch, Team Deathmatch, Tournament, Capture The Flag (all modes also in vanilla Q3), Harvester, One Flag CTF, Overload (these three from Q3's Expansion Pack Team Arena included in vanilla) Elimination, CTF Elimination, Last Man Standing, Double Domination and Domination (all of these additions)
The game is compatible with many of the mods and maps done for Q3. Because OA is not finished, some of the many mods created for the original game couldn't be compatible.
There's also a "missionpack" addon, which acts as the game's stand-on for Quake III: Team Arena.
A reboot, called OpenArena 3 is being developed, with a release date to be announced.
OpenArena has examples of:Several tropes which apply to Quake III: Arena might apply here as well. Also, these tropes, unless noted otherwise, apply to 0.8.8.
- Abandoned Warehouse: am_underworks, blitzkrieg3, oa_dm3, oa_reptctf11.
- Animesque: The style of the game, or at least, what it tries to be.
- Artificial Brilliance: Bots will gib your body if you were carrying the Kamikaze holdable.
- Batman Can Breathe in Space: There're some space platform levels and just a bunch of the characters (Sarge, Grunt, Grism and S_Marine) have a space suit.
- Battle Royale Game: The Elimination, CTF Elimination and Last Man Standing modes:
- Last Man Standing is regular Deathmatch split in shorter rounds where every player fights on their own in order to eradicate the rest of the players and be the last player on foot when the round ends.
- Elimination follows the same model and ruleset as LMS, but splits players in two teams, and each team fights to eradicate the enemy team.
- CTF Elimination follows the same model and ruleset as Elimination, but also adds the Capture the Flag flags, and thus rounds can also be won by capturing the enemy flag.
- BFG: Subverted. The game's version is less bulky than in the source, but it's still a Plasma Gun in steroids, and is still the most powerful weapon in the game.
- Chainsaw Good: The Gauntlet. Like in the source material, it's a wrist-mounted circular saw.
- Chinese Vampire: Kyonshi, who was inspired by another hopping chinese vampire.
- Competitive Multiplayer
- Deadly Rotary Fan: Found in the Deathmatch level pxlfan.
- Death Is Not Permanent
- Death Trap: Some Deathmatch levels such as oa_dm2 and have these.
- Defeat Equals Explosion: Any player who dies while carrying the Kamikaze holdable powerup. When dying, (and if they're not gibbed) they will produce a huge explosion which shakes the arena.
- Flight: The namesake item, only available in two maps. (am_thornish and am_spacecont)
- Fragile Speedster: The Scout rune makes one of its carrier. In exchange for increasing the carrier's speed, it negates armor, and disallows the carrier to pick up armor.
- Gradual Regeneration: The Regeneration powerup.
- Grappling-Hook Pistol: The Grapple, now an official item.
- Gratuitous French: Beret, when he dies, says "Et merde" ("And shit" in French).
- High-Pressure Blood: In spite of it's art direction, the blood is more detailed and more chunks appear from a single fragged player.
- Joshikousei: Ayumi.
- Lightning Gun: The Lightning Gun.
- Mayincatec: oa_dm5 and am_mckinleyish2 take place at some ruins.
- More Dakka: The Chaingun. The Machinegun is the starter version of the Chaingun.
- Ms. Fanservice: Many of the females.
- Nail 'Em: The Nailgun.
- No Plot? No Problem!
- Panty Shot: Ayumi, when she's killed.
- Rollerblade Good: Ayumi.
- Last Man Standing, Domination and Double Domination are taken from the namesake gametypes from Unreal Tournament and Unreal Tournament 2004.
- cbctf1 and oa_ctf4ish (Capture The Space) take inspiration from the Quake III: Arena map q3ctf4.
- delta (Mission Over Mars) takes inspiration from the Quake III: Team Arena map mpteam6.
- pxlfan (The Big Fan of Death!) takes inspiration from the Unreal deathmatch map DmDeathFan.
- oa_reptctf11 (Colliding In The Factory) takes inspiration from a third-party map for Quake III: Arena, reptctf11.
- oasago2 (Sago's Castle) takes inspiration from a third-party map for Unreal Tournament 2004, CTF-TFC-Solemn. The same is true for am_spacecont and am_thornish, taking place in remake of other UT third-party maps, DM-1on1-Contact and CTF-Thorns*.
- One of the frag messages from the bots is "<player> is death incarnate".
- The oa_dm* levels are the Quake 1 Deathmatch levels. These levels were GPL'd by Id for Quake's tenth anniversary. dm6ish (The Dark Zone) and ce1m7 (House of Cheethon) are also adaptations of dm6 and e1m7 from the original Quake.
- The hydronex* (Hydrocapture) maps are loose adaptations of Unreal Tournament's CTF-Hydro16.
- Skin Swap: Plenty of examples.
- Space Marine: S_Marine, Sarge, Grunt and Grism.
- Stripperiffic: Some of the females, such as Angelyss, Dark, Rai, Nekoyss, Tanisha.
- Suicide Attack: The Kamikaze item, when used.
- Thanatos Gambit: The player can set this one by getting killed (but not gibbed) and letting some seconds to pass, after which, the skulls explodes and everyone in it's radio area is killed, or at least, hurted enough to get killed.
- Took A Level In Manliness: Up to 0.7.7, Beret was a flamboyant boyscout. In 0.8.0 onwards, he was redesigned as a macho commando.
- Use Item: The Teleporter, Medkit, Kamikaze and Invulnerability items.
- Why Am I Ticking?: Hit an enemy with a Prox Mine, (or many, for amplified effect) and in 10 seconds, more or less, there's a high chance that he will blow into pieces.
OpenArena 3 has examples of:
- Adjustable Censorship: Not only for violence, but also an option for partial nudity, switching certain characters to more modest variations.
- Art Evolution: Most of the older material is going to be revamped, with a style going completely towards anime, rather than just being influenced by it.
- Animation Bump: Additional player animations are supported.
- Fanservice Pack: Some of the characters get this coming with the Art Shift.
- Lens Flare: The sun now gets this.
- Pointy Ears: It might as well be called Jigokumimi Arena.
- Retraux: To some degree. It's intended to look from the year 2000 for both stylistic and technical reasons; in particular, first-generation PS2 games and other PC games of that year.
- There's an option to render the game as through a 3Dfx Voodoo video card, complete with texture limits, dithering, pixel filtering and scanlined gamma correction.
- There is also a PC-98 postprocess shader that renders the game in 16 dithered colors.
- Snake People: Lamia
- This Is a Drill: The saw gauntlet is replaced by a drill gauntlet as the melee weapon of the game.