WoWDB

An arcane charge, generated by Arcane Blast, Arcane Missiles, and Arcane Explosion, and consumed by Arcane Barrage and Evocation:

Arcane Blast
Generates a charge.
Arcane Blast's damage is increased by 50% per charge, and its mana cost increased by 150% per charge.

Arcane Missiles
Generates a charge.
Arcane Missiles' damage is increased by 50% per charge.

Arcane Explosion
Refreshes charges and has a 30% chance to generate a charge if at least one target is hit.

Arcane Barrage
Consumes all charges.
Arcane Barrage's damage is increased by 50% per charge, and it hits 1 additional nearby targets per charge for 50% damage.

Evocation
Consumes all charges.
Evocation's mana generation is increased by 25% per charge.

Stacks up to 4 times and lasts 10 sec.