Warhammer 40000 Dark Heresy is a role-playing experience set in the grimdark Warhammer 40,000 universe, following agents of the Inquisition rooting out heresy and corruption. Players investigate threats and battle enemies across the franchise's brutal sci-fi setting.

The game emphasizes the Inquisition's grim mandate, blending investigation and combat as players work to uncover and eliminate threats to the Imperium.