In January 2006, Irrational was bought by Take-Two Interactive and its name was changed to 2K Boston, with its Australian studio becoming 2K Australia. In 2010, however, Take-Two had a change of heart and allowed 2K Boston to adopt its former name again (seeing it as having better brand-recognition potential, given the succesful history of the developer). The Australian studio was eventually separated from Irrational and became a part of 2K Marin.
In February 2014, Levine announced on the company's website that he would "wind down Irrational Games as you know it" in an effort to focus on smaller, narratively driven games distributed digitally under the Take Two umbrella. This process entailed laying off most of the company and putting together a much leaner team of developers and was finalized in early 2017, with the founding of Ghost Story Games, a team of roughly two dozen developers led by Levine. As of that moment, Irrational Games has been effectively defunct.
- System Shock 2 (1999) — Due to this being a collaboration with Looking Glass Studios, the game even uses the same basic engine as the first two Thief games.
- The Freedom Force series:
- Freedom Force (2002)
- Freedom Force vs. the 3rd Reich (2005)
- Tribes: Vengeance (2004) — A prequel to the Tribes series & sequel to the Starsiege series.
- SWAT 4 (2005) — The fourth installment of Sierra's tactical shooter series.
- SWAT 4: The Stetchkov Syndicate (2006) — An expansion pack.
- The BioShock series (except BioShock 2, which was outsourced to 2K Marin):
Tropes about this developer:
- Developers' Foresight: Irrational are well-known for their thoroughly in-depth gameplay mechanics that account for a lot of different situations the player can find himself in.
- Sophisticated as Hell: The below original pitch for BioShock lists "scare the hell out of people" as one of the primary objectives. This is the only instance of swearing in the document, which is otherwise extremely professional.
- What Could Have Been: Lots of examples of this in the company's history. The Insider section of the studio's website gradually reveals a lot of them, mostly unrealized ideas or unused concept art.
- System Shock II was originally suppossed to feature a level set outside the ship, in the vacuum of space. It proved technically too demanding for the Dark Engine and the idea was eventually droped.
- The original pitch for BioShock had a very different setting, backstory and plot.
- Sometime in late 2005 and early 2006, Irrational Games used the existing SWAT 4 engine and assets as a proof-of-concept basis for their next game project, preemptively titled Division 9. It was supposed to be a Survival Horror shooter with a squad-based nature (much like SWAT 4) and set in... a noirish city after a mysterious Zombie Apocalypse. The project was eventually scrapped in favour of concentrating on BioShock. Three years later, Valve published a game with the same basic idea. Makes you wonder if Division 9 would've been similarly succesful years ago...
- BioShock Infinite had gone through a lot of different concepts. Word of God even noted that the team had to cut "five or six games" worth of material from the final product.
- For Want of a Nail: Had an adventure game based on Star Trek: Voyager not been cancelled by Viacom when Looking Glass Studios was developing it in the mid 1990s, Ken Levine, Jonathan Chey and Rob Fermier might not have left the studio to found Irrational Games.