Bethesda has filed a lawsuit against Warner Bros. and Behaviour Interactive, claiming that the Westworld mobile game is "a blatant rip-off" of Fallout Shelter.

Bethesda is seeking for a portion of the Westworld game's profits, and for it to be taken down from the Apple App Store and Google Play Store. What is the basis for the legal action?

Why The 'Westworld' Mobile Game Is A 'Fallout Shelter' Rip-Off

Bethesda's first foray into mobile games, Fallout Shelter, is a management simulator that was announced and released at E3 2015. It found massive success, giving Bethesda motivation to keep making iOS and Android games.

However, the recently released Westworld mobile game, based on the hit HBO science fiction series, is allegedly looking to illegally ride the success of Fallout Shelter.

In the lawsuit, filed in a Maryland U.S. District Court, Bethesda claims that Behaviour used "the same copyrighted computer code created for Fallout Shelter in Westworld." Bethesda added that it tapped Behaviour to develop parts of Fallout Shelter in 2014, and the developer used some of the designs and artwork in the Westworld mobile game.

"Working with the same copyrighted computer code used by Fallout Shelter, Westworld has the same or highly similar game design, art style, animations, features and other gameplay elements as Fallout Shelter, all of which are owned by Bethesda," the studio alleged in the lawsuit. Other noted similarities include gameplay, 2D cartoon characters in a 3D environment, and underground facilities.

Adding to the evidence that Behaviour used Fallout Shelter code is the fact that some of the bugs in an early version of Fallout Shelter are also found in the Westworld mobile game.

Bethesda said that Behaviour simply took the Fallout Shelter code and made some aesthetic changes to fit the Wild West theme of the Westworld mobile game.

Lawsuits On Similar Video Games

Bethesda is not the only recent video game company to have filed a lawsuit for similarities between video games.

Another high-profile case on video game copyright infringement is the feud between PUBG Corp., the company behind PlayerUnknown's Battlegrounds, and Epic Games, which created Fortnite.

Last month, PUBG Corp. filed a copyright infringement lawsuit against Epic Games, claiming that Fortnite copied several elements of PlayerUnknown's Battlegrounds.

The timing of the lawsuit, however, raised questions, with the sudden lawsuit possibly because Fortnite was starting to widen its lead over PlayerUnknown's Battlegrounds in the Battle Royale genre.