How do sunder modifiers for size and weapon work?

Question

With sunder,

The wielder of a two-handed weapon on a sunder attempt gets a +4 bonus on this roll, and the wielder of a light weapon takes a -4 penalty. If the combatants are of different sizes, the larger combatant gets a bonus on the attack roll of +4 per difference in size category.

If a medium sized character wielding a two-handed weapon was attempting to sunder a large creature's light weapon, what would the creature size and weapon size modifiers be?

Does the large creature get a penalty for the light weapon? Or does that only affect the "sunder attempt" and not the opposed attack roll?

Does it matter that the large creature's light weapon would be a one-handed weapon for a medium sized creature?

Answer 1

• Medium size creature

  • Smaller creature (no bonus)
  • Two-handed weapon (+4 bonus)
  • Total bonus: +4

• Large size creature

  • Larger creature, one size category larger (+4 bonus)
  • Light weapon (−4 penalty)
  • Total bonus: +0

So, ceteris paribus, the Medium creature gets a +4 bonus over the Large creature. Both combatants, sunderer and sunderee, are making the same roll with the same rules, and yes, the Large creature takes the −4 Light weapon penalty.

If a Medium creature wielded the Large creature’s Light weapon, they would be forced to treat it as a One-handed weapon. They therefore would not take a −4 penalty from it being Light. However, they would also not get the +4 bonus for being Large, so they would wind up with the same +0 bonus.