A board game based on Portal is due to be released later this year.
Portal: Uncooperative Cake Acquisition Game is being created by Cryptozoic Entertainment, a company previously responsible for board game versions of Assassin's Creed, The Walking Dead and Batman Arkham City.
However, Cryptozoic president Cory Jones told Polygon that, rather than being one of the company's own designs, the Portal board game is actually a Valve creation, with an internal team at the Steam developer working on the game's mechanics.
The result is a strategy game for two to four players, each controlling an Aperture Laboratories test subject as they attempt to earn the chance to "test in the most desirable test chambers."
According to Jones, Valve already had "a really solid, functioning game" in place when the company approached Cryptozoic about the product.
When asked how much of the game was Valve's input, he stated: "I think they could've done all of it internally, eventually," noting that Cryptozoic only "sharpened up" the design, offering "minimal input".
The game will include custom play pieces familiar to Portal fans, including test subjects, sentries, weighted Companion Cubes and cake.
Portal: Uncooperative Cake Acquisition Game is currently scheduled for release in the fourth quarter of 2014.