Damage Reduced applies to any physical damage remaining after Bone Armor and then Energy Shield have been applied; it does not apply to Crushing Blow damage or Sacrifice damage to self. 
- Effectiveness is reduced when applied to physical damage applied by the following missile attacks:
- When DR completely negates pure physical damage, it does not matter if Amplify Damage or Decrepify then reduce Damage Resist or Damage Reduced by %, since there is no damage to which DR % can be applied.
- It is possible to equip enough DR to significantly reduce or negate non-critical physical damage of normal monsters even in Hell, particularly when combined with -% Damage. However, this is not the case when significant +% Damage is applied by skills or Champion or Unique monsters, particularly when DR % is subsequently reduced as well.
- When an attack applies both physical damage and magic, fire, lightning, cold or poison damage and DR > physical damage, the excess is applied to the sum of non-physical damage after Resist and Absorb have been applied   (only applies to first frame of poison damage). 
- For example, an attack applying 50 physical damage, 50 fire damage and 50 lightning damage to a target with DR 100, Fire Resist 50%, Lightning Resist 50% and +20 Lightning Absorb would result in the following:
0 physical damage (50-100 < 0)
- 25 fire damage (50 * 100-50 /100)
5 lightning damage ( (50 * 100-50 /100) - 20)
- Excess DR (-50) is then applied to 30 total damage, resulting in 0 (30-50 < 0) damage before up to 20 healing from +20 LA.