I’m working on a custom class that wants to have Prestidigitation for flavor reasons, but also has enough Thievery to potentially have the straight up Pick Pockets skill, which got me thinking and searching and I found this thread: http://autarch.co/forums/ask-autarchs/prestidigitation-question
Great question! There's no official ruling.
If a Thief-type wanted to use Prestidigitation to pick pockets “hands free,” I’d allow them to do at their standard target value for a Thief. That would make for a very powerful pickpocket, as he could essentially steal without needing to approach or bump into his “mark”.
If a Thief-type was willing to use both his hands and his magic, I’d give them +2 on their roll.
Which I think is great!
This led me to re-read the Picking Pockets rules (if you roll less than half your target number, you’re noticed), and I started to wonder if that +4 bonus counts as a reduction in target number (so we can just put the adjusted number on the sheet) or not (so we need to separately track the chance of being noticed).
Then I decided it shouldn’t matter. I feel like the chance of being noticed should be based on a separate surprise roll by the target - they WILL notice, eventually, that their purse is gone, the question is whether they react in time to figure out you’re the one who stole it. This also gives particularly alert characters a better chance interact with thieves.
We can add some modifiers to the roll:
-1 if the thief succeeds on his Pick Pockets roll (possibly -2 if he succeeds by 5 or more)
+1 if the thief fails the PP roll by 5 or more (possibly +2 if he fails by 10 or more)
-1 if the thief is using “hands free” pickpocketing by prestidigitation
any situational modifiers (crowded streets -1, lots of guards around +1, etc).
And now I am happy.