Fortnite developer Epic Games escalated its battle with Apple (NASDAQ:AAPL) by filing an antitrust complaint in the European Union (EU) over the fees Apple takes for in-app purchases made from apps downloaded from its App Store.

Although the two will face off in court in May, Epic is making its war on Apple’s payment system a global affair, having filed similar lawsuits against it in the U.S., Australia, and the U.K.

Characters battling at sea in a Fortnite video game.

Image source: Epic Games.

Last summer, Epic Games bypassed Apple’s fees by allowing Fortnite players to pay the developer directly for any in-app purchases. Apple’s cut of such payments typically runs as high as 30%.

Although many developers have chafed over the system, none took on Apple for fear of losing access to the platform. That’s part of the argument Epic is using in filing its lawsuit, writing in a blog post:

Apple has not just harmed but completely eliminated competition in app distribution and payment processes. Apple uses its control of the iOS ecosystem to benefit itself while blocking competitors and its conduct is an abuse of a dominant position.

Apple responded to the end run around its App Store fees by booting Epic Games from the platform, leading to lawsuits and countersuits. Epic is still unavailable from the App Store.

Apple argues the fees help the App Store remain secure, and Epic’s efforts at bypassing the system violate the guidelines that apply to all developers accessing the system.

Although Epic has suffered a significant loss of Fortnite players after being booted from the App Store and the iOS operating system, the video game developer says it’s not seeking to levy any monetary damages against Apple, only that fairness and competition be restored to the system.

Epic CEO Tim Sweeney said, “What’s at stake here is the very future of mobile platforms.”