For my article on thieves, I decided to come up with eight additional skills as a homebrew option.

I came up with 92.

So here they are. Some I thought up (although I doubt more than one or two are actually original); some ideas came from future editions of D&D, some from OSR resources, and some from homebrew sites. The idea is not to introduce all these skills into your game—they’re optional skills you can offer a player if it fits their character concept. You can take away a canon skill to replace with the new skill, if you’re worried about game balance; or you can just let them have an additional 1-3 skills.

This list is based on the idea that the AD&D1e thief includes not just thieves and assassins, but spies, treasure hunters and archaeologists, criminal investigators, scouts, scholars, actors and other performers, writers, and merchants. But it emphasizes criminal and intelligencer activities.

For this list I shall refer to thief skills as Exploits, because I think that’s cool. Base chance of success at Level 1 is given; then the chance goes up 5% each level until maxing out at 80%. I use crits on percentile dice; a roll of 1-5 is a critical failure, a roll from 96-100 is a critical success.

Act Natural: This is looking like you belong in a location you’re not supposed be in; hanging out in a bar frequented by the City Guard; walking right past the soldier who’s on the lookout for suspicious characters; not looking nervous or sketchy just before you rob the bank. The DM can adjust the chance of success based on factors like wearing the wrong clothes, having wanted posters with your face all over town, or if you’re a Drow Elf. Success means you pass unnoticed for the duration of the scene, at DM’S discretion; failure means you get no special protection and have to take your chances. A critical success means you succeed even if you’re an Illithid or are wearing a giant “I’M A THIEF” sign; critical failure and you’re caught, even if you did nothing suspicious. Base chance at 1st Level: 20%

Alcohol Tolerance: On a successful roll, the thief does not get drunk no matter how much they drink. A roll must be made for each hour of carousing, and if they fail, they are drunk until they sleep it off. At DM’s discretion, this may work for other inebriants and mind-altering poisons, maybe with a penalty. On a crit success the thief is invulnerable to alcohol for the whole evening; on a fail they lose consciousness and get alcoholic ketoacidosis, taking 1d6 damage. Base chance at 1st Level: 15%

Ambidexterity: The thief can use either hand for fighting, picking locks, chopping zucchini, or anything else. They cannot do two things at once with both hands, and they don’t get an extra action. No rolls and no crits, unless you have some interesting ideas (share them in the comments). Useful with Two-Gun Mojo.; thieves with both exploits get a 15% bonus on both. Base chance at 1st Level: 100%, since you’re either ambidextrous or you’re not.

Appraise: The Dungeon Master’s Guide discusses henchmen and NPCs appraising valuables; but a thief should have some knowledge of the value of the things they steal, or at least what they’ll be able to get for it on the Black Market. On a success they know the approximate GP value (within 10%); on a fail they don’t know. On a crit success the value triples (it’s one-of-a-kind or there’s a reward for it); on a crit fail the thief damages or loses the item while examining it, or maybe it’s cursed. Base chance at 1st Level: 25%.

Arson: It’s actually harder to burn down a building than you think. Many set fires just char the rug or affect one room. A successful roll means the thief has set a fire than will burn down a whole wooden building, if there is no intervention. On a fail only part of the building burns, at DM’s discretion. A critical success means firefighters won’t be able to put out the fire, barring magic; a critical fail means the thief set themselves on fire and they take 2d6 damage. Base chance for 1st Level: 30%.

Autopsy: This exploit provides information about a humanoid corpse—cause of death, weapon used, last meal, any diseases, etc. A field autopsy takes 2d20 minutes; an autopsy in a secure location takes several hours. If the thief has specialized coroner’s tools, they get a 10% bonus. On a success they get the information, on a fail they do not. Critical success gets you a fact usually not available in an autopsy, Sherlock Holmes-style (“I discern from these bruises that this orc hails from the Frostbitten Reaches”). Critical fail gives the thief false information and permanently mutilates the body. Base chance for 1st Level: 15%.

Bad Luck: This is true: in Southern California casinos largely patronized by people from East Asia, some people are considered “lucky.” They get paid by gamblers to sit at tables and bring them luck. Likewise, some people are considered “unlucky,” and go from table to table taking bribes to go away. This can be a full-time job.

With this exploit, the thief is unlucky—but the bad luck does not affect them, it affects others. When a thief is within melee range of an opponent, they make a Bad Luck roll. On success, the opponent’s next action will resolve as if they rolled a critical fail. On failure, nothing happens. Either way, the thief still gets their turn; this is a free action, since all it requires is proximity. This exploit may be used once per encounter, on one individual. On a critical success, ALL the opponent’s actions in the encounter critically fail, as long as the thief is in melee range. The thief can exit proximity and then move back in, and the critical failures will begin again, until the end of the encounter. On a critical fail, the bad luck either affects a party member or the thief themselves, DM’s discretion; their next action resolves as a critical fail. Base chance for 1st Level: 15%.

Barrel-Rider: This is a very specific exploit, based on an obscure fantasy novel from the 1930s called The Hobbit. The smuggler, pirate, or thief is skilled at hiding people, including themselves, in sealed barrels, so that those people can be smuggled without suffocating or drowning. This can be accomplished without a Barrel-riding roll.

If you want to be like the execrable movie trilogy version of The Hobbit, and engage in combat while riding in barrels down rapids, then the thief needs a successful Barrel-rider roll to even consider it. On a critical success they need no more Barrel-rider rolls for the rest of the combat; on a critical fail the barrel falls apart.

Base chance at 1st Level: 20%.

Body Packing: This is the real-life term for smuggling small items inside the orifices of your body. Now you might say that anyone can do that—but could you really shove an astrolabe up your must-not-touch and walk around like a normal person without training? I think not. It is up to the DM to determine if a particular object can reasonably be inserted into a particular orifice. Then the thief player rolls: on success it gets in and can be removed later; on a fail it is not inserted. On a crit success, the object cannot be detected even by close medical examination; on a crit fail the object cannot be removed without the specialized surgical intervention of a physic or lay healer. Magical healing will not work, although it’s up to the DM’S discretion if the player comes up with some sort of cunning scheme to remove it. Base chance for 1st Level: 30%.

Brainwashing: This is the subtle art of turning a committed enemy into a committed ally through the application of propaganda, imprisonment, torture, threats, false mercy, and sometimes pharmaceuticals. This only works on intelligent non-player humanoids (minimum INT 8, maximum INT 15). The victim must be imprisoned, and have direct contact with the thief for at least four hours a day for 2d6 weeks. On a successful roll, the victim becomes a believer in the thief’s cause, and will do ANYTHING to achieve it. On a fail, the victim hates the thief, whether they did before or not. On a critical success, the whole process takes only four hours. On a critical fail, the victim tricks the thief into thinking they are converted and once freed remains an enemy. Base chance at 1st Level: 20%.

Burglary: This is the exploit of breaking into a building, stealing loot, and escaping. It is used in two ways. If the heist is taking place in downtime, the roll determines if it succeeds or not. If the heist is being planned by the players and roleplayed as an adventure, then on a successful roll, the operation goes relatively smoothly, barring players mistakes or poor rolls. On a failed roll, things go wrong—the owner comes home, there are unexpected traps, the loot is cursed. Note the players can still succeed on a failed roll, it’s just harder. On a critical success, the burglary goes flawlessly. On a critical failure, the heist goes wrong no matter what the players do. This exploit is a narrower version of the Mastermind exploit. Base chance at 1st Level: 25%.

Card Sharp: The AD&D1e Dungeons Master’s Guide details a very clever way to simulate the characters playing cards: the players actually play cards. ¯\(°_o)/¯ Let’s try a different way. Whatever the card game (you should invent a medieval fantasy world card game that uses tarot cards and, somehow, live chickens), for each hour of gambling the players rolls percentile dice against 50+INT. If they succeed, they walk away from the table with 1d10x what they started with (yes they may just break even). Their chance of winning is greater than 50%, which is more fun and reflects having some smarts and experience—thieves know how to gamble. If they have the Card Sharp exploit, they cheat at cards. For each hour roll against the Card Sharp skill instead. A success means they automatically win 2d10x what they started with. On a fail, they get caught, and a fight breaks out (at lower levels there will be a lot of fights, but that’s a feature not a bug). On a critical success, the player wind 10d10x what they started with and breaks the bank, possibly leading to trouble; on a critical failure, the card sharp themselves is cheated, losing 2d10x what they started with. Base chance at 1st Level: 25%.

Carousing: Why do you need skill to carouse? Did the thief go to Party Academy? I looked up Carouse in GURPS 4e Basic Set: Characters, and learned that the skilled carouser gets a bonus when asking for help or information from fellow carousers at the pub, inn, ball, festival, fête, soirée, parade, jubilee, or clambake.

For each hour of carousing, the player makes a Carousing roll; each success gives a one point bonus to a CHA roll when interacting with individual NPCs; this applies to encounters on the same evening, although the DM may decide the fellow carousers have a positive attitude toward the thief the next day or even later. The maximum CHA bonus from carousing is +5. If the player fails the Carousing roll, there is no penalty and they can try again next hour. Unexpected hijinks from another player can negate the CHA bonus, if people know the thief is in the same party.

On a critical success, not only is the CHA bonus permanent for everyone who was at the party, but word gets around the city/town/countryside and the thief will have a +5 CHA bonus with 30% of people encountered. On a critical fail, the thief and the whole party are now hunted criminals in the city/town/countryside. Base chance for 1st Level: 20%.

City Ranger: For a particular city or town, the thief knows every pub, inn, and hostel; every street and alley; every shop and market. They have contacts all over town, from the servants of the aristocrats to the lowest beggar.

On a successful roll the thief has the information they or the party needs, or can introduce them to an NPC who does. There is no failure penalty, the thief just doesn’t know. On a critical success, the thief gives especially important information for the adventure, or the seed of a new one; or the NPC contact is completely at the thieves’ disposal. On a critical failure, the information is spectacularly wrong, or the NPC contact responds with violence.

A 1st Level thief is a City Ranger for the place they grew up; a new city can be added via six weeks of concerted legwork during downtime. Base chance at 1st Level: 30%.

Codebreaking: Starting at 5th Level, a thief with at least 10 INT can decode an encoded message. They can decode messages in a language they do not understand, but need someone who speaks that language to understand it. This exploit does not work to understand foreign languages or argot, but can be used to decode hieroglyphs and pictograms at the DM’s discretion. Base chance at 5th Level: 20%.

Connoisseur: The thief is an expert in fine wines, gourmet food, quality tobaccos, fine art, music, dance, drama, architecture, and the epicurean life. On a successful roll, the thief gets a +5 CHA when dealing with NPCs who would be impressed with such knowledge. This exploit overlaps with Savoir Faire and Appraise. Failure carries no penalty. On a critical success the CHA bonus is permanent with that NPC, who may become a nuisance pestering the thief with questions and invitations to parties; on a critical failure the thief is exposed as a charlatan and possibly arrested or ejected from town. Base chance at 1st Level: 25%.

Cover: This is the thief’s ability to temporarily pose as a member of another character class, profession, or social caste. On a successful roll they are able to maintain the ruse for one encounter, confidently slinging jargon and getting a +3 CHA bonus with members of that class. They will be able to convincingly answer questions like “where did you train?” and “what do you think of [famous member of the class]?”

On a failed roll the NPCs are suspicious and may seek proof the thief is an actual fighter/magic-user/aristocrat. Whether they rolled successfully or not, if asked to do something impossible, like casting a spell, the thief will be exposed unless the player is entertainingly clever. On a critical success, the NPCs are permanently convinced, even if presented with evidence the thief is a fraud. On a critical failure, the NPCs immediately see through the ruse and contact the authorities/the guild/the crown to prosecute the thief.

Base chance at 1st Level: 20%.

Create Acid: The thief knows enough Alchemy to create one vial of acid that will eat through small quantities of wood. Once per day, the thief may prepare one vial on a successful roll; there is no penalty for failure. The DM may decide to require special materials for this. If thrown on a person the victim takes 1d4 damage.

At 5th Level the thief gains the ability to make acid that eats through a small quantity of metal or stone; this does 1d12 damage when thrown. At 10th Level, the thief can direct NPCs and henchmen to create large quantities of acid.

On a critical success the thief creates one vial of alkahest, a universal solvent that destroys small amounts of any non-magical substance except the vial it’s kept in; this does 2d6+10 damage. On a critical failure, the “acid” explodes, giving the thief and anyone within 10′ 1d8 damage.

Base chance at 1st Level: 15%. This exploit can be combined with Create Poison and Create Lubricant to make Create Substances.

Create Camouflage: This is the art of creating articles of armor and clothing that are patterned to blend in with a particular background, and/or covered with brush. The thief may attempt once per day to turn one piece of armor or clothing into camouflage. There are three varieties of camouflage: forest, desert, and city; the DM may decide to allow others.

When completely camouflaged, a humanoid is hard to see, with NPCs and enemies taking a -3 penalty on Perception checks (which in AD&D 1e are usually just WIS checks). There is no penalty for failing to alter a piece of clothing or armor.

On a critical success the thief is able to create three pieces in one day; on a critical fail the piece of armor or clothing is ruined. Base chance at 1st Level: 30%.

Create Lubricant: Boy, do you have a dirty mind. This lubricant is used to improve the chance of success of Find/Remove Traps/Devices and Open Locks; it will also be helpful for schemes where lube would be useful.

The thief can create one small vial a day on a successful roll; there is no penalty for failing and the DM may require materials. One vial of lubricant increases the chance of Find/Remove Traps/Devices and Pick Locks by 15%; and Find/Disable Large Devices by 5%.

On a critical success, the thief creates the alchemical lubricant Oil of Terebinth, one vial of which will let you slide around a one ton boulder. It increases skill success by an additional 10%. On a critical fail, the Oil of Terebinth gets all over the thief, who is trapped in one spot, too slippery to move or grab anything or escape, until rescued.

Base chance at 1st Level: 20%. This exploit can be combined with Create Poison and Create Acid to make Create Substances.

Create Poison: Gary Gygax didn’t like player characters using poison. Assassins of course can, but they cannot create poison until 9th Level. So the poison a thief can create in this homebrew exploit is weak, must be ingested, and has a detectable taste.

Once per day the thief can roll to create one dose of poison. The DM may require materials. There is no penalty for failure. At 1st Level the poison does 1d2 damage (flip a coin or 1d4/2 round up.); at 4th Level 1d4; at 7th Level 1d6; and at 10th Level 1d8 and the poison is tasteless. The victim gets their Poison saving throw.

On a critical success, the thief creates one dose of the alchemical poison Mercurius Vitae, which is a tasteless dissolving powder that does 3d8 damage if the victim fails their saving throw. On a critical fail, the thief is poisoned and takes the same damage a victim would have.

Base chance at 1st Level: 15%. This exploit can be combined with Create Acid and Create Lubricant to make Create Substances.

Create Shiv: The thief can turn a small stick or bit of hard material into a makeshift dagger. This requires a successful roll and ten minutes of uninterrupted effort. No tool is required. (If the thief had a knife, they wouldn’t need a shiv!) There is no penalty for failure, and they may try once per hour as long as material is available.

The shiv does 1d6/3 damage at 1st Level: 1d4 at 4th Level; and 1d6 at 7th Level. On a critical success that damage is doubled; on a critical failure the thief injures one hand for 1 damage but gets a nasty infection that does 1 damage per day until treated magically or naturally. Base chance at 1st Level: 30%.

Criminal Lawyer: You don’t need a criminal lawyer, you need a criminal lawyer! The thief has a kind of “street smart” knowledge of the law, and on a successful roll gets a +3 CHA bonus when talking to authority figures like judges. Make the player roleplay it: “I can’t be convicted of shoplifting, your honor, it was an emporium not a shop!” There is no penalty for failure.

This exploit can be used separately on each NPC they encounter, once. This only works when the thief is in legal trouble, and is dealing with a member of the legal system. On a successful crit, the thief is immediately released from legal jeopardy and may even get a reward. On a critical miss, the thief is immediately condemned to the appropriate punishment. Base chance at 1st Level: 20%.

Danger Sense: The thief has an intuitive sense of immediate danger. Whenever the party is about to be surprised or ambushed, or will set off a trap, let the thief player make a roll for this exploit. If successful, the character gets one action to call out or do something; if the DM allows marveling, the character gets to call out AND perform an action. Then the danger appears.

If the thief calls out, the other player characters are not surprised and suffer no penalties. A failed roll has no effect. On a critical success, every character in the party gets a pre-surprise action. On a critical failure, the thief freezes in fear, warns no one, and loses their first combat action.

Base chance at 1st Level: 15%.

Dash: In the spirit of the D&D 5e Dash, on a successful roll this exploit lets the thief double their movement range for one combat round. This may be done once per combat. There is no failure penalty. On a critical success the thief gets this ability three times during the combat to use when they will; on a critical failure the thief trips and fall prone in the spot where they started and loses an additional combat round. Base chance at 1st Level: 25%.

Deception: This is the ability to convincingly tell lies to the skeptical. When lying to an NPC, on a successful roll, the thief gets a +3 to CHA for the duration of the encounter; there is no failure penalty. On a critical success, the Charisma boost becomes permanent for dealing with NPCs in the encounter; on a critical failure the NPCs detect the lies and become angry and aggressive. Base chance at 1st Level: 25%.

Detect Gullibility: So you want to pull a con, and you have a number of potential marks. Who’s most likely to fall for it? When encountering an NPC, the thief makes a roll; on success, if the NPC’s INT or WIS is 9 or below, or if the DM considers the NPC to be particularly trusting, the thief will sense it. There is no failure penalty. On a critical success the mark will automatically fall for the con; on a critical failure (1) if the mark is not gullible, the thief will think they are and (2) if the mark is gullible, they still won’t fall for the con. Base chance at 1st Level: 20%.

Detect Lies: The thief can tell if someone believes what they are saying or not, based on physical cues and speech patterns. This works on any race or creature with a sufficiently humanoid face and voice. If the thief cannot see the speaker and can only hear them, the chance is halved. If the thief does not understand the language of the speaker, the chance is halved. If the thief has previously successfully Detected Lies on a speaker, they get a 25% bonus on later attempts.

On a critical success, the thief not only knows if they person is lying, but whether or not the statement was objectively true. On a critical failure, the thief believes a lie. Base chance at 1st Level: 15%.

Detect Loot: The thief is a treasure hunter with a nose for troves. In a room or a 30’x30′ area (whichever is smaller), when searching for valuables, on a successful roll the thief will beeline straight to the largest (rather than most valuable) cache of items. On a failure, the search proceeds normally. This works on hidden items as well as items in the open. On a critical success, if the treasure is hidden behind a secret door or other concealment, the thief is able to immediately access it without an additional roll. On a critical failure, the thief is confused and useless for finding loot for 10 minutes. Base chance at 1st Level: 20%.

Detect Snitch: The thief has an uncanny ability to tell if an NPC is betraying them, the party, the thieves’ guild, or any other group the thief is part of. The thief can make a Detect Snitch roll on anyone they meet, although the DM can impose limits if the player is becoming annoying.

On a successful roll, if the NPC is a snitch, traitor, or spy, the thief intuits it. If they are not, the thief gets nothing. If the roll fails, the thief gets nothing. Note that the thief does not get any proof the person is snitch.

On a critical success, the thief can prove the treason, or can easily find proof. On a critical failure, the NPC is a traitor, and the thief gets nothing. Base chance at 1st Level: 15%.

Continued in Part 2.

Skip to Part 3.