Thief
Thief is a classic stealth dark low-fantasy game series where you play as Garrett, a thief, who gets entangled in supernatural goings-ons, including an Evil Nature God amd his Beastman amd Druid army, a Steampunk version ofbthe Adeptus Mechanicus, and fanatics obsessed with warhammers.. It also has a fanmade tabletop setting for the original setting, from before the series was given a shitty reboot set in a Victorian Era instead of Art-Deco Steampunk Medieval.
Games
Thief: The Dark Project
The original, packed with horror elements and some forced combat sections since the devs didn’t expect a stealth game to work (Thief is the grandpappy to all stealth games so they never really expected it’s success)
Originally a sword and sorcery RPG inspired by Doom and Quake called Dark Camelot it eventually grew into a stealth game.