Gamespot heeft een redelijk uitgebreide preview gemaakt van Thief 2, waarin ze het o.a. hebben over de verbeterde engine en AI.

Stukje over de AI van de wachtposten:The AI of human guards has been reworked to be more realistic. Sentries no longer exhibit the "frustrated" behavior of those in the original Thief. If a guard can't dispose of you for whatever reason, he or she will run off to sound the alarm or get help. Pathfinding has also been improved to mimic reality, and guards will raise their awareness if level they come across something out of place, like a knocked-over plate. In fact, the sentries will even relight any lamps Garrett has extinguished with a water arrow.