Lutris

Lutris is the glue layer of Linux gaming: it manages Wine prefixes and runner versions for you, pulls community install scripts that encode the fixes a game needs, and unifies GOG, Epic (via integration), Battle.net launchers, and emulated titles in one library. When a Windows game isn’t on Steam, Lutris is usually how you get it running without hand-tuning Wine yourself.

It’s a power tool with power-tool rough edges: install scripts are community-maintained and occasionally stale, debugging a broken prefix still means reading logs, and it won’t fix games that fundamentally don’t work under Wine (kernel anticheat titles, mostly). For Steam games, just use Steam’s Proton directly — Lutris is for everything else.