Step Die System Probabilities

During one of my recent playtests, one of the testers with extensive scientific credentials expressed some misgivings about the statistical underpinnings of the resolution system of Spark RPG.  In appreciation for his concerns, I decided to spend a few hours and produce a comprehensive probability chart so this would be out in the open.

The basic system is that two different people will roll dice and add a static bonus to their result.   The size of die can be D4, D6, D8, D10, D12 or D20.  The bonuses scale from +0 to +6.  This leads to a total of 1764 potential permutations on the chart I have below. For reference, the X axis is the actor and the Y axis is the reactor; with the probability in each cell equal to the chance that X will succeed in the conflict.  I hope this will be of some use to someone.  If you find any errors, please don’t hesistate to notify me so I can make the appropriate corrections.

Spark Probability Tables



Posted in Blog of Legend, Home, Spark, The Process of Design.

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