Fuzzy rules

14 December, 2007 at 6:19 pm (game design) ()

I’m talking precisely about rules that are fuzzy with regards to the setting, not rules that are hard to understand or anything.

An example of exact rule: Climb in d20. It tells exactly what one can achieve with a climb roll an how difficult it is.

An example of fuzzy rule: Profession, not considering the part on earning money, in d20. It tells roughly what character can do but does not include particular difficulties or durations or such (because there would be too much to list, but that is not relevant).

My argument is that exact rules are prone to breaking the game and hence being ignored. I probably could also provide some arguments that tell exact rules are actually preferable, I don’t actually think they are nearly as compelling and so would likely set up strawmen anyway.

The breaking happens when some task clearly in the province of the skill but not covered by the exact rules comes up. Like, say, two characters are trying to climb atop a 50 feet castle wall. The important bit is who gets there first. You could habe both chars roll those 7 to 4 climb rolls that the rules imply. Or you could simply roll one opposed roll. Seven to four isn’t lot. What about if the thing climbed is 500 feet high. Still rolling? I’m certainly not.

Likewise: Mass combat in any game without specific rules to handle it. Creative use of skills, spells and other character abilities. Diplomacy.

With fuzzy skills, I can simply ask for a roll and state difficulty, together with consequences of failure and success, with little need to consult a book or such. Like using profession (general) in a war situation: Roll it as a special aid another that affects the entire army if you beat the opposing general. Or roll to guess the ambush, DC 20 for it being possible but unlikely for a random person to notice. Or perform DC 15 to get the lady talking to and interested in you. Or roll farming to get your crops look impressive enough that the samurai believe you are able to pay your debts, so you won’t be slain right away.

This does mean that there won’t be a one-to-one mapping between the char’s running speed and relevant abilities. Or the estimated jumping distance and relevant numbers. Instead the GM makes a call about the difficulty of the feat (jumping that is pretty easy, DC 5) or asks players to make the call (“How difficult is it to jump 5 ft. without a running start?”). Or doesn’t even use clear measurements, because it is not like the characters know those anyway. So, pit traps can be measured straight in difficulties (DC 15 to jump over, 25 to jump out of there once in, +2 if someone is ready to grab you if you get high enough, +n if smart tools are used, …).

I certainly prefer fuzzy rules. They don’t create logical inconsistencies or huge rollfests as often as exact ones. They do give more responsibility to the GM and possibly players, though, which is something I can and will live with. YMMV. Credit goes to Thalin for making me think.



  1. chattydm said,

    I find fuzzy skill checks exceedingly boring to play out unless the players and DM are agile storytellers (which we aren’t as a group).

    Not surprisingly I’m more of a fan of exact skills that have expanded applications from what the core books describe.

    I like to know in advance what can be done in the system and not let this at the whim of the DM (i.e. my very subjective whim).

    For that matter, Iron heroes’ Skill section describes numerous combat application for all skills such as Appraise to spot a weakness in an armour and Bluff to convince an opponent to hesitate in his attack….

    However, I completely agree that exact rules for skills creates severe limits and broken effects (Like IH’s intimidate that allows a charismatic character to browbeat the strongest creatures with no ressources expenditure, at will)

    But I’d rather improvise based on exact rules than on fuzzy ones.

    It’s a matter of preference and far from me the intention of saying my way is better…

  2. Tommi said,

    I don’t find fuzzy rules particularly arbitrary. I mean, they are, but they don’t feel that way.

    Reasons, as least potential ones:
    1. I GM a lot. I don’t make the decisions arbitrarily or based on whim, but instead on what feels correct in the setting and what creates good game (the heuristic is not too simple, though).
    2. I have played a lot of homebrewed games and GM’d lots of them. Since it is a huge pain to write down exact skills, I didn’t do it, and it worked fine.
    3. I am transparent. I tell difficulties to players, barring few very unusual conditions. I roll in open. If they want to criticise me, I will listen. If one of them knows more about something and corrects me, I live by that.
    4. Further, I also tend to tell the consequences of failing before rolls are made. Not exactly, but on a general level, like “You’ll fall down and will be swept away by the river if you fail.”

    I think 3 and 4 can help any game feel less arbitrary.

    Another way is to make skills as exact as possible. It works best for niche games or subsystems. I have built and might build quite formal dungeoncrawling- and combat-focused game, just for the fun of building one. Stuff like rolling survival or ride, where each success negates one random encounter on the way to the cave. Fail search roll and trigger a random encounter or many but find whatever there is anyway. Roll cave lore or notice to find that the moss is dangerous, otherwise it gets automatic surprise.

    I takes a whole lot of dedication to build a functional exact system which covers many cases well. I don’t anyone has done it. For example: Social rules in current D&D are plain broken.

  3. Not a design blog. « Cogito, ergo ludo. said,

    […] game will be full of exact rules. Every skill shall have a clear and explicit use. In addition to that, and to avoid the problems […]

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