Tuesday, May 8, 2012

Game mechanics: percentiles

Early on in gaming I never really liked percentile rolls. I didn't really like percentile based systems. I liked die rolling with gimmicks. For some reason in my mind percentile rolls seemed very bland to me.

In the course of game design (home brew) I sat down and started applying chances of success based on skill rolls and combat. Looking at average percentages for success.

I caught myself doing it a lot with d20 games. Calculating percentage to succeed, making every +1 to hit a 5% bonus in my head.

Now I see that a lot of die rolling is just that. A gimmick. They can be fun gimmicks involving funny shaped die or combinations of die. But in the end its just a statistic for gauging success. This doesn't mean I don't enjoy dice gimmicks. I now have a new appreciation for percentiles as a simple to the point type of rolling.


  1. nice gaming strategy ! and ideas ! good one!

  2. Well, one of the downsides with the percentile dice is that your probability curve is a flat line. The odds of a 50 are identical to the odds of a 100.

    Mechanics that use multiple dice added together, or with successes that add up, give you a more interesting probability curve where an average result is far more common than a high or a low result.

  3. I think his point is that it doesn't matter if its a straight probability or a curve. In any given roll there is a specific percentage chance you will roll what you need to succeed. So, for example, there is no difference between requiring a 9 on 2d6 or requiring a 76 on percentile dice. One (2d6), has a curve, the other (percentile) doesn't, both are 76% likely to fail and 24% likely to succeed.