You are fighting in conditions that do not allow free movement.

Effects by Weapon Type

One-handed melee piercing or bludgeoning weapon:
  • -1 to hit
One-handed slashing weapon or 2H piercing weapon:
  • -2 to hit
  • -1 to damage
Two-handed slashing or bludgeoning weapon:
  • -4 to hit
  • -2 to damage
  • Extremely difficult to wield effectively

Deflection

You take half your to-hit penalty on deflects with your weapon (at least -1).