I don't have a lot of dice yet, just a basic set of polyhedral dice:
- 1d4
- 1d6
- 1d8
- 2d10
- 1d12
- 1d20
Sometimes an ability or save calls for a die that I don't have.
Strike, Unarmed
[...]
Damage
- A Medium character deals 1d3 points of nonlethal damage with an unarmed strike.
- A Small character deals 1d2 points of nonlethal damage.
[...]
Source: http://www.d20pfsrd.com/equipment---final/weapons/weapon-descriptions/strike-unarmed
Belladonna
Type poison (ingested); Save Fortitude DC 14
Onset 10 minutes; Frequency 1/minute for 6 minutes
Effect 1d2 Str damage, target can attempt one save to cure a lycanthropy affliction contracted in the past hour; Cure 1 save
Source: http://www.d20pfsrd.com/gamemastering/afflictions/poison/belladonna
Is it okay to substitute a d2 for a d4, or a d3 for a d6? I'm worried that maybe I'm overlooking some of the math behind the probability distribution.
When I'm substituting a d2 for a d4, I rule that rolling a 1 or 2 equals a 1, and rolling a 3 or 4 equals a 2. I use the same principle for d3 substitutes or any other substitute I have to make.