Eidos recognise that sound is a "very important factor" to Thief, and so is feedback from guards, who also can be difficult to hear so it's a "double-edged sword" for Garrett. Loot is purposeful.
The team want the world making sense and so loot placement should make sense. Thief has an economy and so acquiring gold is a must to pay for equipment.
"Yes. You can complete the game without killing anybody, or without knocking anybody out, or without causing an alert," confirmed lead level designer Schmidt in an interview with . For those stealthy playthroughs you'll definitely need to watch your step, and those of the guards.
"Looking at the time Thief came out, sound was a very important factor," he said. "We recognize that. The environment around you will have an impact on sound, so soft patches of grass or carpets, they make almost no sound at all, even when you are running. Regular surfaces like stone and wood have a different layer of sound. There are things that make a lot of sound, like water. It splashes more when something goes through it."
"As for the guards, feedback from what they say is very important. You can tell if they heard something or saw something and why they are suddenly moving about. You will also hear the footsteps of the guards, but their footsteps are handled the same as Garrett's--they will be muffled on grass or carpet. So it's a double-edged sword in those areas. Also, if you are in a covered area, you will not hear the sounds as easily."
"So we are taking the sound design very seriously. It is very important to the feel of the game."
Schmidt promises we'll even get a 'loot bragging room' where our more outlandish swipes of collectibles will be on display to make us feel like a thieving big shot. We get money directly from pocketing gold but also fencing items we've pinched, if you want to trade them in.
He also talks about having no 'safe' states for sneaking as detection is rather analogue: "Even though the game has a light and darkness kind of binary look to it, it is much more analog than that. There is this middle state as well where you are kind of exposed. There are several states and the analog value comes from how the eye works."
"Are you moving, are you standing up, are you crouching. A lot of this matters in how we detect you. And peripheral vision is involved. If a guard sees something move out there, he is going to look in that direction. It is a much more slow reaction if they aren’t sure, but if you are right in front of them, they will react much faster," he explained.
Check out thebetween Daniel Windfeld Schmidt and Shacknews for more on Thief's mechanics.