Yeah, the issue is they have a Linux game client, but they don’t have a Linux version of their launcher… so you have to use Wine/Proton/some kind of compatibility layer (and you have to do some work to get the files you need to make that happen), but it’s even more convoluted than that. Just to give you an idea… https://www.reddit.com/r/2007scape/comments/11q8mly/how_to_run_jagex_launcher_on_steam_decklinux/