The Perks

Each thief comes with their own perk set. These perk sets represent the skills of the thief in particular. Each set comes with 5 perks, all of which compliment each other.

Trivia

 * Most perk decks are made to be useful in both stealth and loud situations. The exceptions to these (which are all loud only) are: Muscle (apart from the Intimidate perk in situational areas), Biker, Retributionist, Sociopath, Anarchist, and Raver. Even then, those that can be useful in stealth are mostly outshadowed by better perk sets.
 * 6 of the perk sets (Courier, Captain, Sharpshooter, Gambler, Raqis, Raver, and Fugitive) require DLC.