Editing Samsara:Contests (section)

===Variation: Switch the Bones===
By changing the type and number of dice rolled, one can change the probabilities of certain result and thus the “feel” of the game.

*One could roll 2d6 instead of 1d12.  This would keep the same range of possible outcomes, more-or-less, but due to the shift in probability distribution from flat to bell-curved (well, triangular, actually), the results will tend more toward the middle, with a roll of 7 as the most likely outcome.  The effect of this variation would be to favor the more capable actors in a contest as the random factor of the die will be diminished.  This would make for a grittier game, with less wild occurrences.  On the other hand, that also means that the most likely raw outcome is a success, unless you shift the results table down.

*By rolling 2d8, one would also tend to reduce randomness and favor the more capable, but with a greater possible range of outcomes.  This would somewhat counter-act the first effect and allow a greater possibility for wild, unexpected occurrences.  This variation is then a mix between grittier and wilder.  If you use this variation, you might want to shift the results of the contest roll by two places since the average roll will be a 9.  So 9 should result in .33 checks, 10 in .66, and so on.  If you don’t do this, then everybody will start doing very much better in contests.  Which is fine if that’s what you want.

*3d6 just increases the variation from above: an even wider range of possible outcomes with a much more pronounced probability curve (a real curve in this case).  Again, you might want to shift the results of the contest roll as the most likely result of 3d6 is a 10 or 11.