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Old 05-17-2018, 02:43 AM   #21
Join Date: Feb 2005
Location: Berkeley, CA
Default Re: Some questions on Luck with modifiers.

The value of a single extra roll instead of 2 varies with how hard what you're trying to do is. Basically, the odds of the first roll helping is (chance you succeed), the odds of the second roll helping is (chance you succeed) * (chance you fail the first roll).

My experience is that players save luck for the rolls they're expected to make and fail at, and for negating criticals (at least 91% chance the first reroll does the job), so the second reroll is a lot less valuable. I'd probably say:
  • One reroll and pick the better: -20%.
  • One reroll and you must keep it: -25% (most of the time, you're rerolling something that was already a failure, so unless you crit fail or margin of failure matters, keeping the second roll is NBD).
  • Cannot reroll criticals: -20% (even if rerolling a critical would be the best use for the luck, it's highly probable that you'll find some use for that luck).
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