From: sos@oz.plymouth.edu (Steffan O'Sullivan)
Subject: FUDGE Dice
Reply-To: sos@oz.plymouth.edu (Steffan O'Sullivan)
Organization: Plymouth State College - Plymouth, N.H.
Date: Sat, 19 Dec 92 18:40:05 GMT

Andy Skinner has proposed an alternate dice system that is so neat I'm
tempted to make it the official version.  Looking for feedback.  (I'll
probably post this again after the New Year so those already gone will
have a chance to comment, too.)

Andy proposes using 2d10 and the following table:

Roll:    <2  2-3  4-5  6-7  8-9  10-12  13-14  15-16  17-18  19-20  21+
-----------------------------------------------------------------------
Levels:  -5   -4   -3   -2   -1     0     +1     +2     +3     +4   +5

The "Less than 2" and "21+" columns are because Andy then proposes we
add modifiers to the die rolls, not the levels.  This would work in the
2d10 model because each result contains 2 or 3 different number
results.

The math looks like this:

Chance of getting your level:  28%
Chance of getting above your level: 36%
Chance of getting below your level: 36%

Specifically:

Chance of getting a +/-1: 15% each
Chance of getting a +/-2: 11% each
Chance of getting a +/-3:  7% each
Chance of getting a +/-4:  3% each  (Critical result)

(This means there is a 58% chance you'll get your trait level, or just
barely above or just below it, and 80% chance you'll be within +/-2.)

This is much gentler than 2d6, which (if you graph it) shows a much
bigger jump in the middle of the graph.  2d6 also does not lend itself
to modifying the die roll result, and modifying the level makes for a
very bumpy progression.

The 2d10 table looks very nice when you show modifiers (BTW, you can
safely go to +/-3 modifier in this system, too - which makes FUDGE a
little less grainy):  (the columns labeled (-) and (+) are simply
totals of all results below and above your trait level):

         Result above or below relevant trait (+ to die roll):
Mod:  -5   -4   -3   -2   -1  (-)    0  (+)   +1   +2   +3   +4   +5
+0     0    3    7   11   15  (36)  28  (36)  15   11    7    3    0
+1     0    1    5    9   13  (28)  27  (45)  17   13    9    5    1
+2     0    0    3    7   11  (21)  26  (55)  19   15   11    7    3
+3     0    0    1    5    9  (15)  21  (64)  19   17   13    9    6

In contrast, examine the same thing, adding a +1 to LEVEL, instead:

Mod:  -5   -4   -3   -2   -1  (-)    0  (+)   +1   +2   +3   +4   +5
+0 L   0    3    7   11   15  (36)  28  (36)  15   11    7    3    0
+1 L   0    0    3    7   11  (21)  15  (64)  28   15   11    7    3
+2 L   0    0    0    3    7  (10)  11  (79)  15   28   15   11    7
      (and 3 percent at +6)

Notice how jumpy this table is compared to the one above: the odds of
getting your trait exactly are much more drastically reduced the
further from 0 mods you go, as are the chances of getting below your
trait.  (BTW, both tables are simply reversed to show negative
modifiers - that is, you'll get -1 17% of the time in the -1 to die
roll mod system, etc.)

Any comments on this?  Have I explained the math clearly enough?  The
only problem is that d10s are harder to find, and the table harder to
memorize, but I think the math may be worth it.

Comments?

-- 
  - Steffan O'Sullivan		         sos@oz.plymouth.edu
Newsgroups: rec.games.design