Crumble Undead is a spell that requires a magic level of 39 to cast and costs 2 air runes, 2 earth runes and 1 chaos rune. It has a max hit of 16. This spell can only be cast on undead enemies, such as skeletons, zombies, ghost and shades. Crumble Undead is a good way to train magic, as it costs fewer runes than Earth Bolt (same if you are wielding a staff of earth) and hits as hard as Earth Blast. However, this spell cannot be autocasted except with a Slayer Staff, Staff of the dead, Staff of light or Void knight mace.

It is highly recommended against Vorkath, as the spell instantly kills the Zombified Spawn it summons during the fight.

Trying to attack a non-undead NPC with Crumble Undead says "This spell only affects skeletons, zombies, ghosts and shades".


Spell cost
2Earth rune2Air rune1Chaos rune122
Combo runes
1Chaos rune2Dust rune108
2Air rune1Chaos rune2Mud rune512
2Air rune1Chaos rune2Lava rune120
2Earth rune1Chaos rune2Smoke rune188
2Earth rune1Chaos rune2Mist rune206
2Earth rune1Chaos runeStaff of air112
2Air rune1Chaos runeStaff of earth112
2Earth rune1Chaos runeMist battlestaff112
1Chaos runeDust battlestaff102
2Air rune1Chaos runeMud battlestaff112
2Air rune1Chaos runeLava battlestaff112
2Earth rune1Chaos runeSmoke battlestaff112