Bell Curve Rolls

1d20 roll oftentimes do not accurately represent the abilities of characters, with the d20 roll they are just as likely to roll a 10 as a 20, or in fact a 1. In truth, they should probably be more likely to have an "average" result.

3d6 instead has a bell curve result spread, meaning that a 10 is much more likely than the extremes. However, this also means that a 1,2,19, and 20 are no longer possible.

Automatic Successes and Failures

This means that a result of 3 now counts as a "critical fumble" and an 18 as a "critical success" where normally applicable.

"Taking 20"

Since 20s are no longer possible, take 20 has been replaced with 2 new options, "take 16" and "take 18". As with the rules for taking 20, you can only take 16 and 18 when you have plenty of time, when you aren’t distracted, and when the task carries no consequences for failure. For a check that normally requires a standard action, taking 16 uses up 1 minute and taking 18 uses up 10 minutes.

The rules for taking 10 remain unchanged.

Threat Range

Because it’s no longer possible to roll a natural 19 or 20, the threat ranges of weapons change in the bell curve variant. Refer to the following table. The exception to this is games using the Critical Cards rule. A roll of 3 or 18 are the only way to draw a card.

Old Threat Range	New Threat Range
20	16-18
19-20	15-18
18-20	14-18
17-20	14-18
15-20	13-18