Life leech
Life leech is a utility effect that can turn a percentage of damage dealt into Hitpoints restoration. Life leech can occur actively through some special attacks or more passively through chance on hit effects. This effect is often sought by advanced players to increase the margin of error during harder content, or increase sustainability on longer outings. Some powerful monsters possess methods to leech health from players in return.
Not all sources of life leech are equal and each method may have unique limitations. For example onyx bolts (e) cannot trigger when facing undead monsters and the Saradomin godsword can restore health when fighting some enemies which are completely immune to the sword's damage like a kurask.
Sources of life leech often share a similar graphical style, a visible upwards flourish above the target when triggered in combat. This makes them easy to spot compared to attacks that do not trigger the effect.
The following methods can provide a percentage of damage dealt as hitpoint restoration. Template:/Sources
Cost
Passive life leech methods are often prohibitively expensive, each having an associated cost-per-hour for continual use. These methods tend to be reserved for content that generates profit at a higher rate than this cost.
| Source | Name | Cost Per Hour |
|---|---|---|
|
Guthan the Infested's equipment | [a] 22,000 |
 |
Blood Rush | 885,600 |
 |
Blood Burst | 1,387,200 |
 |
Blood Blitz | 1,411,200 |
 |
Blood Barrage | 2,002,800 |
 |
Sanguinesti staff | 963,000 |
 |
Amulet of blood fury | 1,836,464 |
| File:Onyx bolts (e).png | Onyx bolts (e) | [a] 2,609,700 |
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Special Attacks
Life leech through special attacks does not have an associated cost but is less consistent. These special attacks can still miss or hit for low amounts of damage and may not heal as much or as often as expected.
Because the Saradomin godsword and Ancient godsword have minimum restoration amounts it becomes possible to calculate how much health and prayer restoration they'll provide on average every minute. A lightbearer will double special attack regeneration and should be strongly considered when using one of these weapons as it doubles the restore potential as well.
| Source | Hitpoints/minute | Prayer/minute |
|---|---|---|
|
4[a] | 2[a] |
+ 
|
8[a] | 4[a] |
|
10 | 0 |
| +
|
20 | 0 |
NPCs with Life Leech
Some monsters have a life leech mechanic that a player may have to deal with uniquely during a fight. This usually displayed as a 
with the amount healed above the monster's head but should not be confused with other healing effects that use the same graphic.
- Corporeal Beast - When the smaller magic projectile successfully hits, it will heal itself a small amount.
- Dark energy core - Leeches up to 13 health per player of all players adjacent and heals the Beast by the same amount.
- Nex and Cruor - Using blood spells during the third phase.
- Rune dragon - Occasionally uses the onyx bolt special effect, where it heals itself 100% of the damage dealt.
- Sarachnis - Leeches 10 health when successfully hitting a player with an attack.
- Vorkath - Vorkath's acid pools leech health from players to himself, up to 10 per tick.
- Zebak - Zebak's blood clouds will leech health every tick a player stands next to one, as well with certain invocations Zebak gains access to blood magic spells.
- Phantom Muspah
- Vardorvis - Auto-attacks heal Vardorvis for 50% of the damage dealt.
Exceptions
There are some instances in which players cannot leech health from certain enemies or bosses:
- Zebak - Has immunity to Blood spells and other sources with the life-leech tag.[1]
- Tumeken's Warden and Elidinis' Warden cannot be healed off of blood spells.
- The wights fought during the final act of Desert Treasure II - The Fallen Empire are unaffected by life-leeching effects.[2]