Anti-Cheat Locks Steam Deck Out of Marvel Tōkon Fighting Souls Beta
The open beta for MARVEL Tokon: Fighting Souls went live today, and within hours the Steam Deck community discovered the game has a problem no amount of Proton tweaking can fix: it refuses to boot. Easy Anti-Cheat is blocking SteamOS entirely, returning a “No anti-cheat module can be found for this game and platform” error that has held up across every Proton version tested, including experimental, and even survived manual EAC installation attempts. For a fighting game built for quick pick-up-and-play sessions, this is a hard wall — not a performance issue, not a settings adjustment, but a binary compatibility lock that only the developer or publisher can unlock.
Two Weeks Until Launch, Zero Days of Deck Access
Arc System Works has a strong track record with Steam Deck ports — Dragon Ball FighterZ and Granblue Fantasy Versus both run on the handheld with minimal friction — which makes this exclusion feel like an oversight rather than a deliberate choice. Unlike the performance issues that plagued Halo: Campaign Evolved on Steam Deck, this is a pure compatibility lock — the beta’s failure across the entire Proton compatibility matrix suggests the EAC build simply wasn’t compiled with Linux flags enabled. The full game launches August 6, leaving less than two weeks for Arc System Works or publisher PlayStation to push a patched anti-cheat module. If the final build ships in its current state, Steam Deck owners face an ugly fork: dual-boot Windows or skip one of the year’s biggest fighting game crossovers entirely.
Fighting Games Need Suspend/Resume — Anti-Cheat Kills It
The Steam Deck’s suspend-resume feature is a natural fit for fighting games, where matches are short and sessions slot neatly into commutes or lunch breaks. Anti-cheat software that requires a persistent online handshake undermines that entirely, even when it works. When it doesn’t work at all — as with this beta — the device loses a whole genre, echoing the launch troubles of Avatar: Legends on Switch where another fighter found itself fighting its platform instead of its opponents. ARC System Works’ cel-shaded engine runs well on the Deck’s APU, as Guilty Gear Strive has already proven. The hardware is ready. The security config is not. That distinction matters because it means the fix is entirely on the software side: a recompiled EAC runtime with Proton support. Whether that arrives before August 6 will determine whether Steam Deck owners get to play or get to watch.