Certain Affinity

Certain Affinity's creation was announced in December 2006. The studio was founded by ex-Bungie employee Max Hoberman. In addition to staff from Bungie, it also includes ex-members of companies such as Microsoft, Red Storm, Origin, Electronic Arts, Digital Anvil, NCSoft, and the now-defunct Midway Austin and Ion Storm Austin.

The studio's first work was in creating two additional multiplayer levels for the popular Xbox game Halo 2. These maps, called "Tombstone" and "Desolation" (which comprised the "Blastacular Map Pack") were the last Halo 2 maps to be released; they are remakes of levels from the original Halo, called "Hang 'Em High" and "Derelict" respectively. They were released for Halo 2 on the Xbox Live on April 17, 2007. These maps were not released for Halo 2 Vista, but were replaced with two new maps exclusive to Halo 2 Vista: "District" and "Uplift". Certain Affinity worked closely with members of Bungie and Microsoft Game Studios during the development of these two maps.

Certain Affinity started working on another project in November 2006, which was revealed to be an unannounced original IP game in the action role-playing game genre.

Certain Affinity's first original game was Age of Booty, a downloadable real-time strategy game released on Steam, Xbox Live Arcade and PlayStation Network. The title was published by Capcom on October 15, 2008.

The company helped Valve port Left 4 Dead to the Xbox 360.

In 2009, the company announced the completion of Halo Waypoint, developed in conjunction with 343 Industries.

The company worked on the "Defiant Map Pack" for Halo: Reach, released on March 15, 2011.

The company announced its new game, due to release in summer 2011, called Crimson Alliance, at RTX 2011.

Certain Affinity also partnered with 343 Industries again for the development of Halo: Combat Evolved Anniversary, which was released exclusively for Xbox 360 on November 15, 2011.

At RTX 2012, Certain Affinity announced that the studio was working with 343 Industries again on developing the Forge map-making tools for Halo 4.

At RTX 2014, Certain Affinity showed off its involvement in Halo: The Master Chief Collection with the reveal of one of the six remade Halo 2 maps, Coagulation, along with a new vehicle, the Gungoose.

In 2017, Leyou Tech invested $10 million in Certain Affinity to develop an original game.

In March 2024, it was announced that Certain Affinity would be laying off 25 employees, or 10% of the company's workforce.

On October 18, 2024, Certain Affinity was acquired by Keywords Studios. The acquisition include a team of 180 employees based in the U.S. and Canada. Certain Affinity will continue to operate under its current leadership, including CEO Max Hoberman and President and COO Paul Sams.