In June 2018, Bethesda Softworks filed a lawsuit against the game's developer and publisher; Behavior Interactive and Warner Bros. Entertainment, claiming that Westworld was a ripoff of its own game Fallout Shelter, released in 2015 and also developed by Behavior Interactive. Bethesda had claimed that copyrighted code had been reused and even a bug which was present in an early version of Fallout Shelter could also be found.

On December 12th, 2018, a notice had been filed in federal court that both sides had reached an "amicable" resolution and would bear their own attorney's fees and costs.