Deathmatch Arena is the official Multiplayer Episode of Quake and the only episode that can't be played in normal Single Player. The only thing connecting these levels, besides numbering, is this Episode. This means that there is no focus on a single theme, levels range from idBase to Runic and Terracotta. It consists of 6 levels total.
The main intent of this episode is simply to combine all of the Multiplayer levels into one episode, thereby allowing for easier access when wishing to select a Multiplayer level without having to cycle through the Single Player levels.
Much like the rest of the game outside of Episode 1: Dimension of the Doomed and the Introduction level, Deathmatch Arena is not included in the Shareware releases of the game. No teaser levels were included for Deathmatch because it would have become too large to download. Plus it gave people a further incentive to register their game. 
- According to Tim Willits, he came up with the idea to have extra Deathmatch levels for Quake. When he originally proposed the idea to the rest of the team at id Software, they responded by saying that creating these levels would be a waste of time. As it claimed, it was only through Willits' perseverance and insistence on their inclusion that the rest of the team was convinced to create these levels. These 6 levels ended up being played more by fans than the rest of the game. 
- These claims have since been refuted and denied by John Romero and other ex-devs of Id Software like John Carmack; as Multiplayer-only levels were a thing since Doom back in '93-'95 era, before Quake's release. According to Romero, Willits' story never occured, the levels have always been intended for use with Deathmatch. 
- American McGee has since weighed in, stating that Tim Willits is giving himself too much credit, declaring himself inventor of something that was more of a team effort. He states the evidence against Tim Willits' claims can be refuted not only by the rest of the team, but by physical records. McGee has stated that tim14.bsp can only increase the skepticism because Willits never contributed a map using idBase (besides E4M1: the Sewage System, which was a Singleplayer map); DM3: The Abandoned Base was created by John Romero and the only level utilizing such textures in the final product. According to McGee, Tim Willits perhaps is suffering from a faulty memory, and that Willits likely has convinced himself of a false history. He wished Willits would simply admit he has made a mistake. 
- Tim Willits has since responded with a video of a level fragment called tim14.bsp as evidence to his claims. He states that he is not wasting any more time arguing over the issue, though he stands by his story. . Tim Willits has since stated that while Doom maps were a thing, he was specifically talking about Quake. He has stated that there is not a single document, prior to his involvement, that had levels dedicated to just Deathmatch. When the maps were made, they were simply made as map fragments. The idea would have been to have both Game Modes, since there was no logic in just having support for one when they could have support for multiple types. While it would take longer to make, as opposed to just making maps that supported all modes, he felt the benefit was that the designer would not be limited by the constraints of a Single Player map.
- Sandy Petersen did not create any levels for this Episode. While he likes Deathmatch, he did not care about it in Quake as he felt that ninety percent of the game was Single Player based. . Petersen felt that Deathmatch levels had to be built with symmetry in mind, that there had to be great restrictions in place, which just led to less creative design than Single Player levels. There wasn't the same encouragement to go through a series of tricky areas, doing such would just dissuade players from going there. Petersen therefore felt Deathmatch levels were, by nature, limited to being more simplistic and easy.
- When Quake was being designed, one of the first maps that was made was a giant cube with one Weapon. Most of the developers outside of Petersen would spend hours just playing on the cube level. Petersen remarked that the players wouldn't like a level that was just a cube. The other developers told Petersen that the players would actually like such a thing, even as minimal as it was, which in turn led American McGee in particular to try to make small and minimalist levels.
- In 2006, in conmemoration of Quake's 10th. anniversary, the source code of the maps was released. Since then, the Id maps appeared in plenty of free-software FPS games: Nexuiz and Xonotic had The Dark Zone, while OpenArena (based on Quake III Arena) had the entire Deathmatch episode plus the scrapped dm7, also named The Cistern.