Some abilities, powers, or effects add boost dice or penalty dice to an ability check. This is written as “Boost-“, “B”, or “Penalty-“, “P”, followed by the number of dice. For example, Boost-1 (B1) adds a single boost die, and Penalty-2 (P2) adds a two penalty dice.

Boost and penalty dice directly cancel each other out. If an effect adds B2 and another effect adds P3, the final effect is P1 (3 penalty dice minus 2 boost dice equals 1 penalty die).

Boost and penalty dice should always be a different color or design from the dice rolled for an ability check so they can be easily identified.

Boost Dice

When using boost dice, after the dice are rolled for an ability check, the boost dice are rolled. The highest value boost die then replaces the lowest value regular ability die, continuing to replace regular dice with boost dice until no replacements can be made. If no dice are lower in value, the boost dice are not used.

For example, if a 4D ability rolls (2, 3, 5, 5) and B2 rolls (2, 4), the 4 rolled on the boost dice replaces the (2) on the ability dice, but the (2) on the boost dice is not used.

Penalty Dice

When using penalty dice, after the dice are rolled for an ability check, the penalty dice are rolled. The lowest value penalty die then replaces the highest value regular die, continuing to replace regular dice with penalty dice until no replacements can be made. If no dice are greater in value, the penalty dice are not used.

For example, if a 4D ability rolls (2, 2, 3, 4) and P2 rolls (1, 3), the 1 rolled on the penalty dice replaces the (4) on the regular dice, but the (3) on the penalty dice is not used.

Other Dice and Boost or Penalty Dice

Not all dice are six-sided; a standard set of role-playing dice include four-sided, six-sided, eight-sided, ten-sided, twelve-sided, and twenty-sided dice. Other dice used as boost or penalty dice behave in exactly the same way, replacing the lowest or highest value regular die rolled.