PlayerUnknown’s Battlegrounds studio PUBG Corp. today dropped its lawsuit against Fortnite creator Epic Games, via Bloomberg. The legal issue took two rival games to the battle royale world of courts and lawyers, but the episode is now over. We do not know why PUBG Corp. dropped the case.

PUBG was the trending game of 2017. It has sold over 44 million copies on Xbox One and PC. The game popularized a new kind of experience, battle royale, where 100 players land on an island and fight until only one is left alive. Fortnite added its own battle royale mode and has since eclipsed PUBG in popularity.

Earlier this year, PUBG Corp. sued Epic Games in South Kora. PUBG Corp. accused Epic Games of copying ideas and systems from PlayerUnkown’s Battlegrounds. It focused on 11 similar concpets, including weapons like assault rifles and shotguns along with UI features like the compass.

Copyright law is complicated. The world of gaming has always focused on trends. When World of Warcraft became a big hit in 2004, we saw a wave of similar massively multiplayer online role-playing games. When League of Legends and Dota 2 started making a ton of money earlier this decade, almost every studio began work on their own MOBA (multiplayer online battle arena). PUBG is the latest catalyst for this cycle. But it is unusual for a game to respond to this copy-cat trend with legal action unless one of the games is a more exact copy.

Blizzard, for example, did not sue MMOs similar to World of Warcraft, but last year it did sue a Chinese knockoff of its hero shooter Overwatch. But that example is a more blatant copy of Overwatch than Fortnite is of PUBG.

Complicating matters, PUBG uses Epic’s Unreal Engine 4 technology. Along with making games, Epic licenses its software creation tools to other developers.