Ubisoft bans Linux and Steam Deck users from For Honor because it "cannot meaningfully deploy protection"
There's not much you can do if you're affected.
Summary
Ubisoft will blocks Linux and Steam Deck from For Honor on September 10th, citing anti-cheat limits.
This move likely stems from anti-cheat incompatibility, not game performance on Proton.
Ubisoft burned goodwill with Linux players, and reopening the platform is uncertain.
Usually, when someone on Linux cannot play an online game, it's down to one of two reasons: either the game doesn't run well despite using Proton, or the game uses an anti-cheat system that's not compatible with Linux. However, this is the first time I've seen a company ban Linux users after years of allowing them to play. Ubisoft has announced that it's going to prevent Linux gamers from playing its title For Honor because it doesn't have the resources to ensure people aren't cheating in the game.
Linux and Steam Deck users will be blocked from playing For Honor come September 10th
Sounds like a rough deal for people who enjoyed playing it on the go
As spotted by GamingOnLinux , Ubisoft published a blog post announcing the new Ranked Dominion mode, plus a rework of Ranked Duel, for its 2017 title For Honor . However, the celebrations are cut pretty short when the company follows up by saying that anyone playing on Linux (and that includes the Steam Deck, which uses the Tux-powered SteamOS) won't be able to play:
"To reinforce a fair competitive environment, the team is introducing additional player safety measures. We are removing For Honor from the Linux platform to ensure a safer environment for our players as we cannot meaningfully deploy protection on this platform. This means that For Honor will no longer be playable on Steam Deck starting September 10th. We will continue to investigate different ways to improve our anti-cheat with the possibility of reopening the platform in the future."
It's likely that Ubisoft couldn't figure out how to make anti-cheat software that would work properly on Linux, so instead of working stuff out, it banned the OS from playing the game online.
Here's hoping that Ubisoft does find a way to "reopen the platform" in the future, but honestly, I feel that it has already burned its goodwill with the Linux community with this move.