[RPG Theory] Re-Rolls

[stevekenson]

It is resolved: a game mechanic that allows for a re-roll of the dice, especially if it involves expending a limited resource (uses per day, points, etc.) should never result in a worse roll than you started with.

Comments

[emessar.livejournal.com]

It also depends on the system and in some cases the specific task being attempted. If the system or situation is essentially pass/fail, then the only reason to use such an ability is if you fail. While the quantity shown on the die or dice may be lower, the result can never be worse than a fail which is equal to the original failed result. This changes if you are in a system or situation where results are more graded. If there is a chance for fumbles, criticals, or "degrees of success", there is a larger variety of situations where the re-roll might be used.

Possible alternate systems:

Reroll failed dice - In a dice pool system where each die is binary, reroll only the dice that didn't make the cut. The stronger your initial roll, the less incentive/effect there is for a reroll since there are fewer failed dice to reroll. This also caps your total to your character's natural potential.

Roll and add to the initial roll - In a dice pool system, such a mechanic might simply give you a set number of additional dice to roll. If the system is d20+number, you might get an additional d20 or alternately some lower die type (d10 maybe), to keep people from getting uncharacteristic results.

Alternately you could set the maximum result from the dice as being the maximum for a single roll so that if you rolled a second d20, the maximum of the two d20 rolls could never exceed 20. This would help cap a character to their maximum natural potential, much like rerolling failed dice.