You know something or you know how to do something. Outside of what a thief does, these are the only "skills" I like* to use.
YOU KNOW SOMETHING...It's safe to assume that your character knows more about the world than you do. If your character has or had some kind of profession (soldier, cobbler, joiner, alchemist's apprentice, etc, etc) prior to the adventuring life, then it's likely they know something more about that than you, their player, does. They probably also know stuff relating to where they are from (townies know more about trade than villagers, villagers probably know a bit more about the local monsters than townies, etc), but that's about it.
There are times when something not immediately obvious is presented the players, be it a puzzle, monsters, location, idea, cult, etc. Ideally, the GM will remember where the characters are from and what they used to do and will tailor how information is relayed to the players based on that knowledge, but I can never fucking remember, so:
1. When presented with something unknown, players are encouraged to ask whether their players might know anything about it, but please be specific and explain why: "does my character know anything about how old it is, given her background in archaeology?" is more likely to get a useful response than, "does my character know anything about this?"
2. There are times when the GM just doesn't know what the character might know. It's possible the character knows something, it's possible she don't. In these cases, reframe the question as a statement: "Morgan thinks this is really old" and then let the dice force the GM to get creative:
Roll a die; you've about a 1 in 3 chance to force the GM to confirm whether or not the hunch is correct (if it's correct now, it's always been and always will be true [haha, fuck you GM!]), but, regardless of whether your hunch is correct or not, you've also about a 1 in 6 chance to have the GM also tell you something about the subject at hand that your character might have put together, given her general knowledge. Memory is, after all, associative.
Obviously, the specificity of the hunch is inversely proportional to the likelihood it is true (the GM is confirming whether or not the entire hunch is true, not if the general sense of the hunch is true or if it's mostly true, etc).
We're talking hunches here and not stuff like observable evidence, no using your hunch on stuff like that. Also: these are usable once a session (unless you are a bard),
YOU KNOW HOW TO MAKE SOMETHING...
You know how to make a certain kind of trap, or you can kludge together a spear that won't fall apart the first time it hits something. Kludged stuff works as well as the standard thing, but is fragile. Kludged stuff require a general formula to put together, and these formulas are a list of broadly defined materials and the amount of time required for assembly. At level 1, Thieves know how to make d3+1 things, Fighters know how to make d3 things, and Magic Users and Clerics know how to make d2 things. This starting knowledge has to make sense given the character's Background and origins. Like, a townie that used to be a clerk and is know a Cleric probably doesn't know how to make traps right off the bat.
Any additional knowledge about how to make stuff is learned through play ("great, you helped them make the spears with the other defenders, you now know how to kludge together a working spear"), and my carousing tables usually offer some useful crafting knowledge.
FORMULA, GATHERING INGREDIENTS
You'll need materials, but these are to be cast in a broad way:
Need: 1 long blade, 1 grip, binding material and 2d3 turns.
Need: 1 grip, 1 relatively tempered, sturdy material bar, stick or the like and d2 rounds.
Need: 3 binding material, enough of the base material to cover the chest and legs of the wearer, 4d5 turns; AC as base material (consult with GM to determine)
kludged exploding junk trap
Need: lots of edged, hard junk, a container, an accelerant, a trigger and 3d3 turns.
So like, anyone can know this formula in the abstract sense (sharp thing + handle + glue = dagger), but when a character knows the formula, they know the formula as the actual knowledge required to build this stuff. Players are encouraged to try out variations (like adding a crossbar to the grip of a kludged sword to make a hilt).
This can get highly involved, with interim components being put together (making hilts instead of grips, making triggers, accelerant, tempering wood to make a proper spear shaft or club body), but we've found the simplest iteration being the easiest to manage and the most conducive to having fun.
Giant bee wax might serve as a binding agent, as might strands from a giant spider's web but a the players should ask when gathering this stuff to confirm, though both could serve other purposes (like giant bee wax might be molded into a container?). I don't worry too much about weight or even space.
The GM is responsible for (a) ultimately determining what might serve well as a material component/ingredient, but ought to be open to a lot of fun variability and (b) determining how much of something is needed (ie, what constitutes a quantum/unit needed to make something). The player should come up with the notation that works best for them and then note the stuff on their inventory, like: enough spider silk to bind three things, or spider silk, 3 binding uses or binder x7 (spider silk, bee's wax, vials of clay golem blood).
ACTUALLY MAKING STUFF
To put this stuff together your character expends the necessary materials and time and then you add d6 + Int modifier and write it next to this item in your character's inventory (so like, "kludged leather armor 4"). This is its "kludge value." A value of zero means it's broken, useless, doesn't work.
After the item is used, struck or put under duress, roll a d6. If you roll at or below the kludge value, nothing happens, if you roll above it, reduce the kludge value by 1. If the thing is one use anyway (like an exploding trap), then obviously it's all used up after the one go but being struck or the like may cause it to break or go off (if it can explode, it will). You make this roll for weapons and armor at the end of combat and only once (not for each hit given/taken).
You can spend some time while resting or while in town to shore up your kludged stuff. Expend whatever materials you and the GM think makes sense, spend some time (probably at least a couple of turns) and roll a d6 again. Roll at or above the kludge value and nothing happens, roll below and increase the kludge value by two.
You can probably sell kludged stuff at a third of the price of the standard gear, but probably only in villages or some rougher towns.
PROPSI used to use a way more complicated crafting system that involved Int checks, the kind of homebrew thing that has got vestigial bits and long, blind alleyways agglomerated together. I ditched that as soon as I read this from +Jack Mcnamee , which is just so good.
*I almost always buckle or forget how much I dislike skills and we wind up incorporating other stuff with which we're dissatisfied, try to fix and then drop entirely.
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