Hitman: Absolution is a third-person assassination game, where action and stealth are treated as equal citizens, granting the player total freedom in the way missions are tackled. Its gameplay is a combination of voyeurism, social stealth, action stealth, and tactical combat. All these styles, as well as the transitions between them, must be challenging and fun to play. This requires an AI that adapts to multiple situations and reacts to the player's actions in a believable way. This presentation explains the rationale behind design choices, and provides detailed information about the implementation of the multiple software layers driving AI and NPC animation in Hitman: Absolution.