What just happened? Bethesda Softworks has filed a lawsuit against Warner Bros. Entertainment and Behaviour Interactive, claiming the recently released Westworld mobile game is a “blatant rip-off” of Fallout Shelter… and they’ve got a smoking gun to prove it.

The suit alleges Breach of contract, inducement to breach of contract, copyright infringement, misappropriation of trade secrets and unfair competition.

According to Bethesda, it hired Behaviour to work on Fallout Shelter in early 2014 and provided the concept, design and overall direction of the game’s mechanics and resulting look and feel. Behaviour provided the implementation and according to Bethesda, all work and materials created by Behaviour for the game are the property of Bethesda.

Behaviour later went on to develop the Westworld game for Warner Bros.

Bethesda believes that the recently released Westworld game for Android and iOS has the “same or highly similar game design, art style, animations, features and other gameplay elements as Fallout Shelter.” Furthermore, Bethesda claims the Westworld game uses the same copyrighted computer code used to make Fallout Shelter.

To highlight this point, Bethesda notes that Westworld even includes some of the same bugs that were present in early versions of Fallout Shelter. In the complaint, the company outlines one such bug involving an out-of-focus camera shot when starting the demo version of Westworld. According to Bethesda, the exact same bug was present in an early build of Fallout Shelter but was fixed before the game was released to the public.

Bethesda says Behaviour and Warner Bros. used its intellectual property without authorization.

In so doing, Behaviour breached its contract with Bethesda and utilized its restricted access to Bethesda’s intellectual property, including Bethesda’s copyrighted code, trade secrets, and other rights, to compress its development timeline, reduce costs, and quickly bring the Westworld mobile game to market, and offer players the widely popular gameplay experience found in Fallout Shelter.

Bethesda is seeking damages in a jury trial.