Attacks can gain bonues based on facing and positioning: Creatures can change facing at the end of their movement or via DM-approved maneuvers. Arc Effect Front Attacks resolve normally Behind Attack rolls have +1 Behind + Flanked Attack rolls have +2
When an attack roll is made against your AC and the result is within 2 points below your AC, the attack does not hit, but instead counts as a Glancing Blow. Any additional effects that would apply on a normal hit do not apply. A Glancing Blow deals half damage (rounded down).
When an attack roll exceeds a creature’s AC by 10 or more, the attack counts as a Brutal Hit. Brutal Hits do not automatically count as critical hits unless otherwise stated. A Brutal Hit deals +1 damage die of the weapon or effect used.