Two-Sided Dice and Fudge Dice

edited February 2009 in Game Design Help
Some related dice questions:

1. Does anyone have any experience with "two-sided" dice in games like Burning Wheel or Storming the Wizard's Tower? Not actual two-sided dice (ie - coins), but six-sided dice marked with two symbols repeated three times ... three skulls and three lightning bolts, for example.

It seems like this might be a little easier to use than regular six-sided dice for games where the number of successes matter, rather than the totals. I guess if you play those games a lot, counting the successes becomes second nature, but if you don't, it can be a little tedious.

I realize this won't always do the trick for those specific games, as it defeats things like open-ended rolls. Just curious if anyone had used dice like this in a game.

2. If anyone has played with dice like this, where did you get them? I can't seem to find any online.

3. For games using Fudge dice, how do the probablities stack up against straight rolls, or dice pools? is there any benefit to rolling larger numbers of dice for a skill-based conflict, if higher numbers simply create more negatives as well as positives?

Comments

  • 1. I'm not sure exactly what you're asking. Have I used special dice like those in games? Or have I played games with 2-sided dice mechanisms? No and yes, respectively. Ryan's new game, Mythender, uses scads of 2-sided dice (it's a low/high d6 mechanism, technically).

    2. I have never seen dice like this. They're of such limited use, I can't imagine I'd drop 15-20 bucks for a cube of 12mm "two-siders."

    3. Again, I'm not sure what you're asking. Fudge dice are d3's, essentially, but with a -2 modifier. 4dF is 4d3-8. At handfuls of more than about 4 Fudge dice, the chance of maxing out on one end of the curve is almost negligible (1 in 3^N, where N is the number of Fudge dice). So the chance of maxing out pluses with 4dF is about 4%; 5dF = 1.2%; 6dF = 0.4%; 7dF = 0.1%; 8dF = 0.02%... So while you can increase the range, the chance of actually rolling anything on one end of the range is very, very small.

    Yes, the mean result of Fudge dice never changes -- it is always 0.
  • edited February 2009
    I used to be able to find at my local Gamekeeper these dice that had a horizontal (or vertical -- how would you tell?) line on three sides, and an X or times symbol on the on the other sides. I used to use them instead of flipping a coin when playing Pokemon with my kids (I hate flipping coins -- they tend to go all over the place). They were nice. There are math dice available from education stores with three addition symbols and three subtraction symbols or three multiplication symbols and three division symbols here's an example). You can also buy blank dice on-line or from school supply stores, and color three sides with permanent markers, leaving the other sides blank.

    Edit: Oooh, Kaplow makes binary dice (three 0's, three 1's). And they even sell them on Amazon.
  • Burning Wheel dice are not D2s... 6s explode, also, if the ability being tested is grey or white, a success occurs on a 3-6 or 2-6 respectively.

    Special Burning Wheel dice have been made (I think there's even a thread here on them). There has been discussion of the most cost effective way of making them, to be pure, they need 5 different face markings (equivalent to 1, 2, 3, 4 and 5, 6). It is possible to do with 4 unique markings, A, B, B, C, C, D, however, while A can consistently be treated as a "6" for exploding dice, D, can not always be treated as a failure (for black shade, C and D are failure, for grey shade, C is failure, for white shade, D is failure).

    Frank
  • As I recall, the Fudge dice came about because it turned out to be relatively cheap to use the mold for the addition/subtraction dice replacing one + and one - side with a blank.

    Frank
  • Posted By: BWA3. For games using Fudge dice, how do the probablities stack up against straight rolls, or dice pools? is there any benefit to rolling larger numbers of dice for a skill-based conflict, if higher numbers simply create more negatives as well as positives?
    Your average will stay the same, but the larger your dice pool the greater chance you have of getting larger magnitude results (that's "further from 0", not just "more positive"). With lots of dice the magnitude's about proportional to the square root of the number of dice, but with smaller numbers like you'd actually use, it's not quite so clean as that. The probabilities are still easy enough - to find your chance of getting a X or better on N dice, do the following:

    s = sqrt(N) * 0.816
    z = (X - 0.5) / s
    look up z in a table of z-scores for normal distributions, like here: (http://www.epatric.com/documentation/statistics/z-score_table.html). If your percentile is e.g. 90th, that's a 10% chance.

    Example: how likely am I to get a 3+ on 8 dice? X=3, N=8. s=2.3, z=2.5/2.3=1.1. Looking up z=1.1 I find the table says "0.8643", which means there's an 86% chance of getting lower than a "2.5", giving about a 14% chance of getting a 3+. The bit where we subtract 0.5 is to deal with all the numbers between 2 and 3 that the dice might roll... they can't, obviously, but the distribution thinks they can, so we just throw all the 2.5-3 results in with 3+.

    Getting -X or worse is the same chance as getting +X or better, of course.
  • Thanks for the responses, all. My apologies if my questions weren't clear.

    I'm aware that binary dice don't work for Burning Wheel specifically, since the 6s are open-ended rolls (and since differing shades have non-binary success numbers). It was just the first game that came to mind where you roll many d6s and count the successes.

    My question was if anyone had any experience using two-sided dice in systems that DON'T have such factors. I haven't heard of Mythender, but I'll look for it.

    Peter, thanks for the heads-up. Those are indeed the kinds of dice I as looking for.

    Although I'm a little disappointed in the available flavors. Xs and pluses and colored sides all do the job, but I was envisioning skulls and fists, or something similarly dramatic.
  • Hollow Earth Expedition uses an even/odd success mechanic, with no frills I'm aware of. They also sell dice that recreate the bell curve of rolling several 2 sided dice together, called "Ubiquity Dice" http://www.rpg.net/reviews/archive/12/12634.phtml
  • edited February 2009
    I had almost forgot -- Exile Game Studio sells Ubiquity Dice, which are 8-sided dice that come in the following varieties:
    • 0,0,0,0,1,1,1,1
    • 0,0,1,1,1,1,2,2
    • 0,1,1,1,2,2,2,3
    The first type is a D2, the second is equivalent to rolling 2D2, and the third is equivalent to rolling 3D2. They're supposed to be nice for dealing with large pools of D2 -- I've heard mention of them being used for Prince Valiant on rpg.net, as well as Exile Game's own Hollow Earth Expedition RPG.

    Edited: Annnnd cross-posted with Wilhelm...
  • Ooo, yeah, Prince Valiant. You flip coins. Totally a D2 mechanic!
  • I guess with any system that relies on even odds when counting successes and no open-ended rolls you could swap out dice for coins.

    But then how would you know you were role-playing? I don't understand.
  • I think the venerable Story Engine uses what amount to D2's counting "odds" as they put it.

  • Isn't 1001 Nights based on odds/evens, so you can use dice with any number of sides?
  • Posted By: BWAMy question was if anyone had any experience using two-sided dice in systems that DON'T have such factors. I haven't heard of Mythender, but I'll look for it.
    Sadly, since I'm still writing it, the only way to look for it is to talk with me. Happily, I'll talk with just about anyone. Feel free to whisper me for contact info (you or anyone else, I'm pretty chatty).
  • edited February 2009
    Posted By: MikeRMIsn't 1001 Nights based on odds/evens, so you can use dice with any number of sides?
    Yep. Brilliant that, actually, given how the color is used (calling the dice "gems" if I recall right, etc.)
  • Posted By: J B BellI think the venerableStory Engineuses what amount to D2's counting "odds" as they put it.
    Yep. And Universalis uses coin-flip dice, I believe. And *blatant plug* so does ...and cast no shadow.
  • The main reason for my question was a game I'm designing (just for my own group). I like dice pools, but I don't like counting to see which dice were successes. Maybe my brain is just not good at quickly recognizing number patterns. I think I'd really like dice pools if it was reduced to something more visually simple, like +/-.

    Ryan, was this the reasoning behind your choice to use these dice in your game? Or are you just using plain ol' d6s? I do see the value in open-ended rolls, like BW's. Is that something you felt your game didn't need? (Efindel, those questions would apply to your game as well).
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