What does it mean when, say, a rat does 1d3-4 damage? Obviously it doesn't heal you when it bites(!) but multiplying for a critical multiplies the modifier too so a confirmed critical would be 2d3-8 which is still negative so it doesn't seem to be just to allow damage on a critical. I'm confused...
A creature, if it hits, will always deal a minimum of 1 nonlethal damage, even if the result of its damage roll would be 0 or less.
The reason the statblock writes out "1d3-4 damage" instead of simply writing "1 nonlethal damage" is because the creature could theoretically receive an increased strength bonus, or increase in size, or another option that would increase its damage to a potentially positive number.
Thank you.
A creature, if it hits, will always deal a minimum of 1 nonlethal damage, even if the result of its damage roll would be 0 or less.
If "MSRD" means "d20 Modern SRD", then a creature does a minimum of 1 point of normal damage.
The nonlethal thing is only in Pathfinder.