I think what mixed me up was this line in the rules:
"Damage (D) A character hitting a foe rolls the number of dice indicated by his weapon's damage rating. He then adds or subtracts any modifiers. This total is the number of damage points he delivers (minimum of one)."
The "minimum of one" is, I think, intended to apply only to the subtractions that some weapons entail (i.e., the cutlass does 2d6-2 damage).
Say I hit an enemy wearing leather armor and carrying a small shield. That gives the enemy an armor rating of 3 (2 for the armor, 1 for the shield).
I hit with my cutlass. So that's 2d6-2 from the cutlass, minus another 3 for the armor of the target. So, 2d6-5. I roll a 5. So, does the target take 0 or 1 point of damage? If I'm understanding the quoted rule above, then the "minus 2" part of the cutlass damage cannot cause the damage to fall to 0, but apparently the armor can.
I reckon I'll just play that it does reduce to 0, makes sense, but I do think that bit of the rules clouds the issue a bit.