Thieves specialize in deceit, treachery, and acrobatics. They can be invaluable where traps must be detected, walls must be climbed, and locks must be picked.

Thieves add +2 to Climbing, Lockpicking, Stealth, as well as Notice or Repair rolls that relate to traps and similar devices. The bonus to Stealth does not apply when the character is in a wilderness environment–only in urban areas.

Savage Worlds Deluxe Edition p. 44