|Release date||3 December 2009 (Update)|
|Drain rate||200 points per minute (1 point per 0.3 seconds)|
|Effect||+2 to +5 levels (for armour)|
-4 to -8 enemy levels (for armour)
Leech Defence, one of the Ancient Curses, boosts Defence by 2 levels when calculating block chance, increasing to 5 over time, and it drains enemy Defence by 4 levels when calculating block chance, increasing to 8 over time.
The boost/drain of this prayer will take anywhere from 1–3 minutes of continuous combat to maximise.
This prayer is extremely useful against powerful, high-defence monsters such as Mithril dragons, or in PVP situations, and is proven highly effective when used against Nomad in the Nomad's Requiem quest.
Leech curses drain one opponent. Following each kill, the leech % resets, and %'s does not carry across opponents. You can maximise an enemy's drain, but upon fighting a new opponent the drain will restart, eventually rising to maximum again. Player boosts do carry across, however, providing that the player is supplied with more drains to sustain the leech.
Because the Defence drain/boosts will reset after each kill, this curse is most commonly used against boss monsters which take a long time to kill, however it is still somewhat effective against lower-levelled monsters.
- According to the ancient hymnal, Leech Defence's verbal incantation is "Reple me vallo hostium." (Fill me with the defence of my enemy.)