Yes, I know I'd said that this would be about plausible level design, but that's taking me rather longer to research than I expected, so instead let's talk about stealth systems. What I want to do here is define the characteristics of stealth in the original Thief games (particularly T1 and T2), compare these to stealth in Thief, and examine how the stealth systems have affected the rest of the game.1
In the beginning we lived as thieves
The easiest way to describe the stealth systems in Thief is to list the ways in which the player could be discovered by the AI. You could be seen, heard, or noticed. By 'noticed', I mean that a guard could become aware of your presence not because they saw you, but because they saw something you had done to the world, such as the dead or unconscious body of a guard. 'Noticing' is probably the area which changed the most over the course of the series: guards in T1 only responded to bloodstains or bodies, but by T:DS they could notice open doors, doused torches and missing loot. Covering most of one's tracks was easy, but hiding bodies was a slower process that frequently caused the player to become more exposed. In the first two games, bloodstains could only be removed by water arrows, forcing the player to balance the risk of a guard discovering them against the cost of the arrow.
In the beginning we lived as thieves
The easiest way to describe the stealth systems in Thief is to list the ways in which the player could be discovered by the AI. You could be seen, heard, or noticed. By 'noticed', I mean that a guard could become aware of your presence not because they saw you, but because they saw something you had done to the world, such as the dead or unconscious body of a guard. 'Noticing' is probably the area which changed the most over the course of the series: guards in T1 only responded to bloodstains or bodies, but by T:DS they could notice open doors, doused torches and missing loot. Covering most of one's tracks was easy, but hiding bodies was a slower process that frequently caused the player to become more exposed. In the first two games, bloodstains could only be removed by water arrows, forcing the player to balance the risk of a guard discovering them against the cost of the arrow.
