Wednesday, July 3, 2013

The Bell Curve Experiment

Consider the range of 3-18, produced by 3d6. Generally speaking, lower is worse, higher is better. Any particular action requires a roll of 3d6. A result of 9-12 indicates the "expected" result, whatever that may be. 3 is the worst possible outcome, indicating a rare and notable disaster occurring, while 18 is the inverse.

This roll can be used to resolve anything. Is there a hiding place nearby? Can I make an impromptu crossbow? How large is that army? How good is this armor? How far can I jump?

Skill (or lack thereof) is represented by rolling more than 3 dice and keeping the highest or lowest scores respectively. This could be a range of -5 to +5, say. A particularly skilled thief may roll 6d6 (that is, +3 dice) and keep the 3 highest when sneaking about. Contested rolls would be made by either party, the roll consisting of subtracting one entity's skill from the other (e.g. two men arm wrestle, one with +1, the second with +3. If the first makes the roll, it is 5d6 keep the 3 lowest. If the second makes the roll, 5d6 keep the highest; they are symmetrical, and the results are relative the roller's interests).

For any given question asked, action taken, or detail implemented, the DM need only define the expected outcome, then roll to find the deviation from this outcome.

I would group the results into the following 7 categories:

3 disastrous
4-5 severe
6-8 unfortunate
9-12 expected
13-15 fortunate
16-17 grand
18 miraculous