At first glance, Monday's fight may not seem so, well, epic. The two companies are expected to debate a proposed court order that could temporarily force Apple to bring Fortnite back to the iOS App Store. Apple removed the game last month for violating its policies after Epic introduced a way for users to circumvent Apple's in-app payment system.
But Monday's arguments reach far beyond these two tech giants. They reflect years of complaints by app developers around the globe who say Apple's tight-fisted grip on iOS app distribution chokes off innovation, and results in unreasonably high costs to consumers.
Apple and Epic did not immediately respond to requests for comment.
The hearing lays the groundwork for what experts say will be a landmark antitrust case against Apple — one that could threaten the profits of the world's most valuable company and reshape the entire digital economy.
As part of its effort to challenge the status quo, Epic has also sued Google, which pulled Fortnite from its app store in August for similar reasons as Apple.
"This case is not just about one video game, but about whether just two companies — Apple and Google — can control the terms of how software is distributed to millions of users," said John Bergmayer, an attorney at the consumer advocacy group Public Knowledge.
Here's what you need to know about the showdown.
Why are Apple and Epic in court?
It all comes down to the way Apple gets paid.
When you make in-app purchases from an iOS app, Apple takes a 30% cut, which Apple says is justified by the service it provides. Apple's contracts prohibit trying to circumvent the rules.
Last month, Epic decided to challenge the rule. In a software update to Fortnite, it encouraged iOS players to buy the game's digital currency, known as V-Bucks, directly from Epic, as opposed to through Apple's in-app purchase system. To sweeten the deal, Epic offered a discount to those who bought V-Bucks directly.
While consumers may have viewed it as a loyalty bonus, Apple saw it as a gross violation of its contract with Epic and an attempt to undercut a key revenue stream.
In a letter to Epic, Apple lawyer Douglas Vetter wrote that Epic wants "all the benefits Apple and the App Store provide without having to pay a penny." He added: "Apple cannot bow to that unreasonable demand."
Apple promptly yanked Fortnite from the App Store and, for good measure, revoked access to Unreal Engine — a piece of Epic software used by game developers and, increasingly, Hollywood, to create lifelike digital scenes and environments. The technology has been used in Disney's recent award-winning series The Mandalorian.
That brings us to Monday's arguments. Epic has called for a preliminary injunction that would prevent Apple from taking actions against Epic. Apple is against the proposed injunction, saying Epic wouldn't be in this sticky situation if it hadn't willfully broken its contract — a fact Epic doesn't deny. (The judge in the case has already granted a temporary restraining order against Apple that forces the com