There's been a renewed interest recently in making GLOG classes that are extensible, like the original Wizard and its schools. I've been part of working on several of these before - Bottomless Sarcophagus' Witch, Oblidisideryptch's Barbarian and Warlock, I even wrote a Bard, so I decided to take a crack at a class I haven't really touched: the Thief. To give it a little more mechanical identity, I've decided to give the thief access to some storygame-esque skills.
While Wizards can warp the fabric of reality, and Clerics can channel the powers of the gods, Thieves are so good that the narrative itself bends to their whims. They can retroactively choose to have prepared just the tool for the job, or set up a trap in just the right place, or realize they've always known the language that the merchants speak. It might rub some people the wrong way, but it's my class and my rules and I think it's really cool to let the Thief have some definition of its own. Of course, other Guilds will provide other ability sets, and hopefully I come back to add more.
These Thieves have Guilds, like Wizards' Schools or Bards' Genres. The Guild you belong to determines the suite of 6 abilities you can rank up in. Each ability has 3 ranks. At level 1, you start with 2 abilities, each at rank 1, and as you level up you both increase the rank of the abilities you have and gain new abilities at rank 1.
Thief
Level 1: Gain 2 abilities at rank 1
Level 2: Rank up an ability you have, then gain a new ability at rank 1
Level 3: Rank up 2 abilities you have
Level 4: Rank up 2 abilities you have, then gain all abilities you don't have yet at rank 1
Hit Die: d6
Specific abilities, equipment, and skills are all determined by the Guild a thief belongs to.
Thieves Guild
Possession is nine-tenths of the law. That last tenth is the tricky bit...
Starting Equipment: 2 daggers, a dark cloak, set of lockpicks, roll 2 extra random items
Skills (2, d6): 1. Acrobat, 2. Bully, 3. Forger, 4. Gambler, 5. Lookout, 6. Pickpocket
Abilities
1: Bag of Tricks
✧: You have a Bag of Tricks, which takes up 2 inventory slots. While you have inventory slots in your Bag that haven't yet been filled with defined items, you may produce a mundane tool of neglegible value from your Bag that will help you solve a current problem. It then takes up one of the inventory slots in your Bag of Tricks. You may clean out and refill your Bag when you return to town.
✧✧: Your Bag now has 4 slots.
✧✧✧: Your Bag no longer contributes to encumbrance.
2: Opportunist
✧: Whenever you would gain advantage to hit, you may also roll damage with advantage.
✧✧: Whenever you would gain advantage on a roll, you may reroll 1s.
✧✧✧: Whenever you would gain advantage on a roll, you may roll 3 results instead of 2 and take the best.
3: Prepwork
✧: On a 1 in 6, you may declare that you've set up a minor environmental effect nearby in an area that you would've had access to within the recent past, and trigger that effect.
✧✧: One automatic success per day, then 2 in 6 for each following attempt.
✧✧✧: 3 in 6 for each following attempt, and you can have retroactively set up effects in any area you plausibly could have had access to at any time in the past.
4: Second Story Worker
✧: You can climb vertical surfaces as quickly as you can walk.
✧✧: Double your move speed and jump distance.
✧✧✧: You can climb upside down as quickly as you can walk. Halve fall damage.
5: Thick as Thieves
✧: You can recruit d4 thugs in town who're loyal so long as they'll get a cut of the loot and are sure they'll make it out alive. They will flee, cheat, or betray you and each other if either of those conditions becomes sufficiently murky.
✧✧: d6 thugs or d4 thieves, each with 1 rank in a random thief ability (besides this one).
✧✧✧: 2d6 thugs or 2d4 thieves, each with 2 ranks in a random thief ability (besides this one).
6: Tricky Fingers
✧: Whenever you try to perform sleight of hand (lockpicking, pickpocketing, etc), failure won't alert anyone who isn't already paying attention to you.
✧✧: You leave no trace of tampering, or specific traces of your choice, when you perform sleight of hand (whether you succeed or fail).
✧✧✧: Whenever someone tries to retrieve or draw an item, you can (on a 2-in-6, with 1 guaranteed success per day) reveal that you actually burgled it from them at some point in the recent past (if you had access).
Seamstresses Guild
You'd be surprised what people let slip when they're in the company of a good listener.
Starting Equipment: 3 sets of fancy clothes, 3 stilettos, bottle of liquor, makeup kit, noble's calling card
Skills (2, d6): 1. Artist, 2. Casanova/Seductress/Them Fatale, 3. Dancer, 4. Gambler, 5. Poet, 6. Seamstress (but for real)
Abilities
1. Con Artist
✧: So long as no one can verify what you’re saying is wrong, you can lie through your teeth and they’ll believe you for at least d6 minutes.
✧✧: d6 hours.
✧✧✧: Even if they can verify, they'll believe you over other people until the end of the duration.
2. Cunning Linguist
✧: Three times, you may encounter a language that the party does not understand, and reveal that you speak that language. Add that language to your character sheet, you are now fluent in it.
✧✧: You can attempt to translate any language you don't speak. The GM rolls a d6 secretly for the number of errors you make in the translation.
✧✧✧: You can crudely communicate with anything that has a language. Gain the ability to speak with (d6: 1. Birds, 2. Clothing, 3. Doors, 4. Gold, 5. Fire, 6. Weapons)
3. Fancy
✧: Fancy clothes give you a +2 AC bonus.
✧✧: Can choose to ablate fancy clothing like a shield; reducing the damage from one attack by d12 points but ruining your outfit in the process.
✧✧✧: Given a short rest, you can make any outfit into a fancy outfit through sheer willpower and coordination.
4. Seductive Wiles
✧: You can keep someone engaged in conversation with you, to the exclusion of all else, for an hour. This makes them less hostile, and on a 2-in-6 they let valuable information slip.
✧✧: You don’t have to roll to impersonate someone in casual conversation, but gaps in your knowledge can still reveal you. 4-in-6 to let info slip.
✧✧✧: You can choose which specific information they reveal, if any, and you can keep them talking for d6 hours.
5. Thick as Thieves
✧: You can recruit d4 thugs in town who're loyal so long as they'll get a cut of the loot and are sure they'll make it out alive. They will flee, cheat, or betray you and each other if either of those conditions becomes sufficiently murky.
✧✧: d6 thugs or d4 thieves, each with 1 rank in a random thief ability (besides this one).
✧✧✧: 2d6 thugs or 2d4 thieves, each with 2 ranks in a random thief ability (besides this one).
6. Tricky Fingers
✧: Whenever you try to perform sleight of hand (lockpicking, pickpocketing, etc), failure won't alert anyone who isn't already paying attention to you.
✧✧: You leave no trace of tampering, or specific traces of your choice, when you perform sleight of hand (whether you succeed or fail).
✧✧✧: Whenever someone tries to retrieve or draw an item, you can (on a 2-in-6, with 1 guaranteed success per day) reveal that you actually burgled it from them at some point in the recent past (if you had access).
Archaeologists Guild
That belongs in a museum! No, *my* museum, not yours... no, not even if you're still using it, now hand it over, it's priceless!
Starting Equipment: Case of maps and pens, wide-brimmed hat, machete, whip, leather armor
Skills (2, d6): 1. Cartography, 2. History, 3. Merchantry, 4. Occult, 5. Religion, 6. Soldier
Abilities
1. Appraisal
✧: You can tell the rough value (within an order of magnitude) and historical/geographic provenance of items, architecture, etc. You know how to dismantle them to get 20% value from the more manageable components, rather than the ordinary 10% for defaced art.
✧✧: You can identify that an object, effect, or creature is magic on sight. Gain the ability to Speak with Art.
✧✧✧: Gain the ability to Speak with Magic.
2. Bag of Tricks
✧: You have a Bag of Tricks, which takes up 2 inventory slots. While you have inventory slots in your Bag that haven't yet been filled with defined items, you may produce a mundane tool of neglegible value from your Bag that will help you solve a current problem. It then takes up one of the inventory slots in your Bag of Tricks. You may clean out and refill your Bag when you return to town.
✧✧: Your Bag now has 4 slots.
✧✧✧: Your Bag no longer contributes to encumbrance.
3. Cunning Linguist
✧: Three times, you may encounter a language that the party does not understand, and reveal that you speak that language. Add that language to your character sheet, you are now fluent in it.
✧✧: You can attempt to translate any language you don't speak. The GM rolls a d6 secretly for the number of errors you make in the translation.
✧✧✧: You can crudely communicate with anything that has a language. Gain the ability to speak with (d6: 1. Birds, 2. Clothing, 3. Doors, 4. Gold, 5. Fire, 6. Weapons)
4. Danger Sense
✧: 3-in-6 chance of acting in surprise round when ambushed, advantage on saves against effects you haven't seen yet.
✧✧: Always act in surprise rounds; always act first in initiative order.
✧✧✧: Once, you may cheat death.
5. Historian
✧: On a 1-in-6, you may declare a historical fact relevant to the current situation (negotiate it with the GM). Whether correct or not, it's believed to be true in the current era.
✧✧: One automatic success per day, then 2-in-6 for each following event.
✧✧✧: 3-in-6, and the historical facts you declare can be outlandish - but your reputation will make them believed.
6. Second Story Worker
✧: You can climb vertical surfaces as quickly as you can walk.
✧✧: Double your move speed and jump distance.
✧✧✧: You can climb upside down as quickly as you can walk. Halve fall damage.