https://www.gamespot.com/articles/bethesda-files-lawsuit-over-westworld-game-calls-i/1100-6459972/

Update: Bethesda has confirmed with GameSpot that it filed suit again Warner Bros. and Behaviour in US District Court. It says the complaint alleges "copyright infringement, breach of contract, and misappropriation of its intellectual property." The publisher also issued the following statement:

"The case arises from Behaviour's development of a Westworld mobile game for Warner Bros. Behaviour had previously worked with Bethesda to develop Bethesda's hit game, Fallout Shelter, and under that contract, Bethesda alone owned all resulting intellectual property, including the game's copyrighted code.