Using the Doom 3 engine as its base, this project became The Dark Mod, it introduced a revamped (and ultimately superior) lockpicking system, brand new locations to explore and all manner of denizens from which to rob and pilfer. The original trilogy of games remain some of the genres best (despite not aging that well graphically by modern standards), but a lack of a fourth sequel eventually put a set of dedicated fans to work. If you like your games with a healthy dose of stealth, then there’s a good chance you’ve played one or more of the Thief games over the years.
