PUBG Corp. filed a lawsuit in South Korea accusing Epic Games of infringing on its copyright with the ultra-popular Fortnite Battle Royale.

PlayerUnknown's Battlegrounds (PUBG) may have set the stage for battle royale games, but Fortnite Battle Royale stole the spotlight. Epic Games' take on the genre has more players, a bigger audience on Twitch, and potentially a larger esports scene thanks to Epic Games' pledge to contribute $100 million to the professional scene. With this new lawsuit, it seems PUBG's creators won't leave Fortnite Battle Royale uncontested.

The games do boast many similarities. Up to 100 players are transported via airplane or "battle bus" to a location featuring a few medical supplies, plenty of weapons, and an ever-shrinking safe zone surrounded by lethal gases or storm clouds. Each player strives to be the last one standing, but how they achieve that goal is up to the player. They can engage in firefights, skulk around the action, or simply hide in a bush.

That's where the similarities end. PUBG is based off military shooters that feature semi-realistic gun mechanics. It takes place in believable not-quite-real-world settings, and lets people choose between a third-person view or first-person perspective. Fortnite Battle Royale is defined by cartoony graphics, a building mechanic that lets adept players build the equivalent to the Sistine Chapel in mere seconds, and casual gun play.

Many gamers were captivated by PUBG when it debuted. It spent weeks atop the Steam charts, shattered records for concurrent players, and dominated Twitch streams. But then Fortnite Battle Royale came around with its free-to-play spin on the genre and usurped its predecessor in all major categories. In other words, it's fair to say that PUBG's backers popularized the battle royale category only to have Epic Games steal the thunder.

So now the fight will leave the digital realm and head to the courts. Though less violent, this battle could be even messier than anything that's happened in either game. PUBG is built on Unreal Engine 4, which means Epic Games could probably find a terms of service violation that would leave PUBG Corp. open to counter-suit--and while they're competitors, both companies are partly owned by Tencent. This is basically a family dispute involving the world's biggest games.

Because PUBG and Fortnite Battle Royale are involved, however, this is a lawsuit to watch. Both are rushing to establish dominance over the battle royale genre before it, like the first-person shooter and MMORPG genres, becomes crowded with new games. The court's decision could make the difference between battle royale being a viable genre, or every title too similar to PUBG risking a lawsuit or having to pay some kind of licensing fee.

We reached out to PUBG Corp.'s parent company Bluehole Studio and Epic Games for comment on the lawsuit and will update if either responds.