Thievery
Typically used with: Agility.
In short: swiping and release. This skill isn't as nefarious as it sounds. Thievery represents the art of legerdemain, pilfering, and escape artistry. This skill can be used to draw a small weapon unnoticed, snatch an item away from a table, pick someone's pocket, and other movements that require the hand to be faster than the eye. It can also be used to slip out of tight bonds or another character's Grab.
Stealing
It's like taking candy from a baby! Except a wallet is usually more valuable than candy. You can roll a Thievery check to deprive someone of their coin purse, swipe an object from a merchant stall, or slide the ring off the countess' finger, all without being noticed. The victim of the theft rolls a Perception check. If your Thievery check is higher, the item is yours. If their Perception check meets or exceeds your Thievery check, they immediately spot what you're doing and get a chance to hold onto the item. If you still want it, you can begin combat and make a Grip check to take it.
You really can't swipe or hide an object that someone is actively watching. You'll need some kind of diversion to make them look elsewhere, for instance, a friend's Perform, Seduce, or Taunt.
If the object is very small or otherwise easy to conceal (e.g. a marble, a dagger, four aces), you gain a +2 bonus on the Thievery check. If the object is large, heavy, or otherwise very noticeable (e.g. a Dachshund, an axe, a sack of potatoes, a longsword), you take a −4 penalty on the Thievery check.
Disarming
You can use a Thievery check to knock the weapon out of someone's hand. Essentially, you're using your own weapon as a tool to swipe the other. Your opponent must roll a Grip check. See the "Disarming" entry in the Tactics section of Chapter 10: Combat. If your Thievery check beats their Grip check, you knock the weapon to the ground. Certain types of weapons, for instance whips and chains, grant a bonus to the Disarm check.
Escaping
You can roll a Thievery check to escape another creature's Grab. See the "Grabbing" entry in the Tactics section of Chapter 10: Combat. Using Thievery to escape from a Grab takes 3 AP. To try to pin you down, your opponent rolls a Grip check. If your Thievery check meets or exceeds their Grip, you're free of the Grab.
You can also try to escape rope bonds, chains and a lock, or a set of manacles. In this case, you're rolling against either the DL of the manacles or lock, or the Craft check of the character who tied you up. Trying to escape bonds takes 3 AP. You can choose to Take the Best if you're tied up and there's no rush to get out.