Chance of Open Wounds can cause target to bleed uncontrollably when applied with a successful weapon attack, draining life and stopping damage regeneration for its 8 second (200 frame) duration. Bleeding occurs even when life drain cannot be applied to target.
- Percentage chance from multiple sources is summed, although when two weapons are equipped only that of the attacking weapon is added (that of the other weapon is ignored). >100% is redundant.
- Applied by any melee or ranged attack with the exception of Blade Sentinel, Blade Shield and the additional arrows of Multiple Shot (only applied by the original two arrows).
- Always applied to another player character, but only applied to other units (monster, mercenary or pet) if their life value changes, either due to damage taken or regenerated. If no damage is taken then Open Wounds will not be applied if regeneration has already been stopped by Prevent Monster Heal.
- Life drain is dependent on the level of the player, mercenary or Iron Golem applying it. Life drain per frame in 1/256ths of a point is currently calculated as follows:
||(9*lvl) + 31
||(18*lvl) - 104
||(27*lvl) - 374
||(36*lvl) - 779
||(45*lvl) - 1319
- Life drain per frame may then be modified depending on the attack used and the target, and rounded down to the nearest 1/256 point:
||Life Drain Multiplier
- Special units are monsters other than normal and minion monsters (Champion, Unique, Super Unique, boss (excluding normal and minion Putrid Defilers) and Evil). Life drain is unmodified against all other targets.
- Although duration is 8 seconds (200 frames), life drain is not applied in the first frame and so points of life drain are calculated as follows:
- Life drain cannot be countered by any form of damage reduction.
- Duration cannot be reduced by Cleansing or Fade.  
- When Open Wounds is applied again before the previous duration expires, duration simply gets reset regardless of the level of the second application: if it is applied at level 80 while it is still being applied at level 60, level 60 damage is still applied for the reset duration (and vice versa).
- Poison Damage and length can be applied separately and simultaneously. 
- Replenish Life and + Life After Each (Demon) Kill from items, and healing from potions, Prayer (including its passive bonuses to Cleansing and Meditation) and Holy Bolt still apply while active.
- Replenish Life from items is a direct counter: Open Wounds applied by a level 30 player's melee attack on another player would result in 109/256 life drain per frame, which Replenish Life +109 would counter entirely; a ranged attack would result in 54/256 life drain per frame, which Replenish Life +54 would counter entirely.