Grievous Wounds

Grievous Wounds is a debuff that reduces all healing received by 40% / 60%.

Sources

Champion abilities

Items

Spells

Ignite (40%)

Notes

Shields are a way of temporarily adding health to a champion that is not reduced by Grievous Wounds.

Type	Heal and Shield Power	Spirit Visage	Revitalize	Grievous Wounds
Health regeneration
Life steal
Spell vamp
Drain effects
Self heals
Self shields
Incoming heals
Incoming shields
Outgoing heals
Outgoing shields
Bonus health

Strategy

Grievous Wounds is generally used to limit or minimize the healing, health regeneration or life steal of one enemy champion ability such as Darius' Decimate, Renekton's Cull the Meek or Volibear's Chosen of the Storm. It can also weaken burst healing champions such as Dr. Mundo, Fiora, Mordekaiser, Swain, Trundle, Vladimir, Aatrox or Warwick.
- Grievous Wounds isn't useful just against champions with in-built sustain. Some champions (examples include most ADCs) can build items that give them sustain, such as Death's Dance, Hextech Gunblade or The Bloodthirster. Grievous Wounds is also useful against them. This is important to notice especially in situations where technically there are no champions with natural sustain on the enemy team, but the enemy ADC has massive amounts of lifesteal to sustain itself during teamfights.
- On the other hand, some champions only have sustain when out of combat. This includes Garen, Tahm Kench, and champions that build Warmog's Armor. Grievous Wounds is not effective against those champions; the most effective way to prevent them from healing is to force them to stay in combat.
- It is important to note that Grievous Wounds also affect healing from outside sources instead of just self-healing. This is especially important against Soraka, which can use Astral Infusion to outsustain her enemies, even if her allies don't have sustain themselves.
Grievous Wounds, alongside Frozen Heart, Randuin's Omen or Warden's Mail, is a great counter to Udyr's Turtle Stance and Xin Zhao's Determination.
Grievous Wounds won't affect Sion's Glory in Death and disappears if a champion dies, though it will still be applied if a champion revives (e.g. Zilean's Chronoshift or Guardian Angel).