BioShock developer Irrational Games is "winding down" in its current form and all but approximately 15 members of the studio will be laid off, according to an update from co-founder Ken Levine.

"I am winding down Irrational Games as you know it," Levine wrote on Irrational's official website. "I'll be starting a smaller, more entrepreneurial endeavor at Take-Two. That is going to mean parting ways with all but about fifteen members of the Irrational team. There's no great way to lay people off, and our first concern is to make sure that the people who are leaving have as much support as we can give them during this transition.

"Besides financial support, the staff will have access to the studio for a period of time to say their goodbyes and put together their portfolios. Other Take-Two studios will be on hand to discuss opportunities within the company, and we'll be hosting a recruiting day where we'll be giving 3rd party studios and publishers a chance to hold interviews with departing Irrational staff."

During the development of BioShock Infinite, Irrational Games employed upward of 200 people. On LinkedIn, more than 100 employees list their current employer as Irrational.

Levine said that he's "deeply proud" of what Irrational Games has accomplished, but that his passion "has turned to making a different kind of game than we've done before."

"I need to refocus my energy on a smaller team with a flatter structure and a more direct relationship with gamers," he wrote in his open letter. "In many ways, it will be a return to how we started: a small team making games for the core gaming audience."

Levine says the new team will focus its efforts on making "narrative-driven games for the core gamer that are highly replayable" and focused exclusively on digitally-delivered content.

"When I first contemplated what I wanted to do, it became very clear to me that we were going to need a long period of design," he wrote. "Initially, I thought the only way to build this venture was with a classical startup model, a risk I was prepared to take. But when I talked to Take-Two about the idea, they convinced me that there was no better place to pursue this new chapter than within their walls. After all, they're the ones who believed in and supported BioShock in the first place."

The BioShock series will continue at Take-Two, Levine says, but in someone else's hands.

"I'm handing the reins of our creation, the BioShock universe, to 2K so our new venture can focus entirely on replayable narrative," he said. "If we're lucky, we'll build something half as memorable as BioShock."

In an interview with Polygon last October, Levine said that the future of development at Irrational was unclear, and that he wasn't looking beyond completion of BioShock Infinite's post-release add-on content. Levine said he'd been "thinking about narrative a lot and the future of narrative and how to make narrative" by playing with and combining story element "primitives."

"I've been working on a concept I call narrative LEGOs," he said, "which is how do you take narrative and break it down. What are the smallest part of narrative that you can then remix and build something out of? Mix and match."

Levine later reiterated that concept at the Gaming Insiders Conference, putting his "thought experiment" into more relatable terms.

"Look at [Bioshock Infinite leading character] Elizabeth," he said. "There are scenes when she performs the same way for everybody who plays the game, every time, always the same. Then there are scenes where we build lots of different narrative content for her. There might be 15 variations of that."

Levine is attached to write the screenplay for a remake of the 1976 sci-fi film Logan's Run for Warner Bros.

Quincy, Mass.-based Irrational Games was founded in 1997 by Ken Levine, Jonathan Chey and Robert Fermier. The studio developed System Shock 2, Freedom Force, SWAT 4 and Tribes Vengeance before being acquired by Take-Two Interactive. The studio was renamed 2K Boston just prior to the release of the original BioShock, and reverted to the Irrational Games name in 2010.

Irrational Games recently completed work on Burial at Sea - Episode 2, the final piece of downloadable content planned for BioShock Infinite. The add-on is slated for release on March 25.

For more on the story of Irrational Games, Ken Levine and the development of BioShock Infinite, read our feature interview with the creator.