NBateman has made a post, detailing all the ways that people have tried and failed to mechanize thieves. In the spirit of perversity and sass, I was immediately overcome with the impulse to make a framework that isn't on the list. This is the result of me listening to that impulse. I make no promises of quality.
Scoundrel
A. Trickery, Locks
B. Scramble
C. Improvise
D. Signature Trick
Locks: You know locks. If a lock can be picked, you can pick it in six seconds. If a lock cannot be picked, you can tell it can't be picked just by glancing at it.
Trickery: You maintain a selection of Tricks on your Trickery Table. Your Trickery Table has six rows and two Tricks per row. It takes eight hours of brisk exercise and skullduggery in a semi-civilized area to swap out a single row of Tricks. You can't have the same Trick on more than [Templates] + 1 rows at a given time.
At the start of each dungeon turn, at end of your turns during combat and whenever instructed to do so by a Trick, roll 1d6 and consult your Trickery Table to see which two Tricks you have access to until the next time you roll. The effects of each Trick are listed below. You get no benefit from erased Tricks until refilled.
Example Trickery Table
1. Ambush & Blackjack
2. Ambush & Blackjack
3. Ambush & Forgery (Deed)
4. Eavesdrop & Disguise (Maid)
5. Lying & Seduction
6. Lying & Explosives
List of Tricks
1. Ambush - Whenever your group rolls initiative, you may erase this Trick from your Trickery Table to surprise the enemy before rolling. Replace it as normal.
2. Arson - Until you roll a row on your Trickery Table that doesn't show Arson, you can see through smoke and safely traverse flames from any and all fires you lit.
3. Blackjack - You are exceptionally lucky at card games. Also, if you bonk someone in the head before they can act during a combat, they must Save or be knocked out.
4. Bribery - You can always tell if someone is willing to be bribed or, if they are actively soliciting a bribe, the minimum amount they would be willing to accept.
5. Climb - Anything a normal person could climb with rope, you can climb without. If you would fall during a climb, you can choose to retreat to where you started.
6. Codes - If you encounter a enciphered message, you can start decoding it. Read off one line every time you roll this result again. You can also encipher messages.
7. Disguise - Pick any person when adding this to your Table. You can impersonate them convincingly while the trick is available, or costume yourself as their peer.
8. Eavesdrop - You may pinpoint the number, species and activity level of living creatures in every adjacent room. You can overhear anything said in the same area.
9. Escape - You may create a brief distraction, redirecting the attention of anyone watching you, then free yourself from any one set of physical or social restraints.
10. Evasion - You may choose not to be hit with an attack. Against a melee attack, you must erase this Trick from your Trickery Table afterward. Replace it as normal.
11. Explosives - When you add this to your Trickery Table, fill an inventory slot with three charges gunpowder (1d6 damage each, stacking) and 30 feet of fuse.
12. Fashion - When you add this to your Trickery Table, fill an inventory slot with fancy attire, granting +1 to Reaction and AC, but only while clean and uninjured.
13. Forgery - When you add this to your Trickery Table, prepare a official looking document. Anyone who cannot issue such a document will think someone who can did.
14. Poison - When you add this to your Trickery Table, gain a dose of
deadly poison (3d6 if ingested). You can safely handle it, or dilute it
into three doses of blade toxin (1d6).
15. Ruses - While talking to someone, get a one word hint about what
they hope is true. When studying a crowd, pick a lie and see who is most
likely to believe it.
16. Seduction - When you add this to your Trickery Table, pick a location. You've convinced someone who lives, works or hangs around nearby that you love them.
17. Smuggling - When you add this to your Trickery Table, pick one inventory slot. Whatever is kept in that slot won't be found on a search. It does not have to be your inventory slot.
18. Sneaking - Whenever you would be discovered while sneaking, you may erase this Trick from your Trickery Table to take back your last action. Replace it as normal.
19. Threats - While talking to someone, know if they are afraid of you and get a one word hint about what else they fear, besides potentially being afraid of you.
20. Traps - Whenever you or an ally would trigger a trap, you may erase this Trick from your Trickery Table to take back the triggering action. Replace it as normal.
Scramble: If you're about to take damage or attempt a d20 roll, you can erase up to [Templates] many Tricks from your Trickery Table to take -25% damage or get +1 on the roll per Trick erased. You must choose whether to do this before rolling.
Improvise: Once per day, you can swap out your current active row on the Trickery Table for two random Tricks generated by rolling a d20 for each. If you roll the same number twice, you may choose anything else on the list as your second Trick. This can explicitly replace an erased Trick without needing the usual eight hours.
Signature Trick: Pick a Trick. It only takes you four hours to switch to or from your Signature Trick and when you Improvise, only roll a single d20: the first Trick rolled is always your Signature Trick instead of being randomly rolled.
