Were you hoping to easily play Fortnite on the upcoming Steam Deck? Well, Tim Sweeney the Epic Games CEO has made it clear that it's not going to happen officially. The thing to remember right now is that both Easy Anti-Cheat and BattlEye do support Linux. Both for native Linux builds and for Windows games run through Steam Play Proton. However, it's all user-space with no Kernel modules.
Fortnite no, but there's a big effort underway to maximize Easy Anti Cheat compatibility with Steam Deck.
The questioning continued and when asked why, Sweeney followed up with:
We don’t have confidence that we’d be able to combat cheating at scale under a wide array of kernel configurations including custom ones.
Another user mentioned it seemed that Epic's CEO didn't trust their own product, Sweeney obviously couldn't let that remain unanswered with:
With regard to anti-cheat on the Linux platform supporting custom kernels and the threat model to a game of Fortnite's size, YES THAT'S EXACTLY RIGHT!
In a number of ways, he's actually right. Windows is closed source, so is the NT Kernel and usually 99% of drivers for it are too. Client-side anti-cheat obviously relies a lot on security by obscurity, so people can't see everything it's doing. This is part of the problem on Linux, where the Kernel and practically all development on it is done right out in the open and it changes rapidly. Developing anti-cheat against such an open Kernel probably isn't going to be even remotely easy. There will be ways though, especially if something like the Steam Deck had a fully signed Kernel and some sort of guarantee it's being used - probably numerous ways smarter people know of.
Really though, overall it doesn't give a lot of confidence for developers who might be looking to hook up their anti-cheat ready for their games to work on the Steam Deck.
The big difference it seems, is the size of the playerbase and how much of a target each game is. Sweeney is not saying it's not suitable as a whole, just that Fortnite is a massive target for cheaters:
The threat model for anti-cheat varies per game based on the number of active players and ability to gain profit by selling cheats or gain prominence by cheating. Hence anti-cheat which suffices for one game may not for another game with 10, 100, or 1000 times more players.
One user followed up by suggesting it was just a case of Sweeney not wanting Fortnite on a "rival's platform", to which Sweeney gave this answer:
Epic would be happy to put Fortnite on Steam. We wouldn't be happy to give Steam 20-30% of its revenue for the privilege. Supporting Steam Deck hardware is a separate issue, but the market for non-Steam-hosted games on limited availability Steam Deck hardware is how big exactly?
With that in mind, you're going to need Windows or to stream it via GeForce NOW on the Steam Deck. At least for games without such anti-cheat, you should be able to use the Heroic Games Launcher on the Steam Deck.
It does mean there's space open for another game to take its place on the Steam Deck officially.