Arcane Damage
Arcane is one of the types of damage in Diablo III. It is purple in appearance, and the corpses of monsters that die from Arcane damage glow with a purple light.
Arcane damage is chiefly dealt by Wizard skills including Magic Missile, Arcane Orb, Disintegrate, Arcane Torrent, and Energy Twister. Other spells (for the Wizard and other classes) may also gain or become Arcane damage with the aid of runestones.
Some monster spell attacks are also Arcane damage, and it's assumed that weapons will also possess Arcane damage as a bonus modifier.
Arcane damage can be resisted, as well as reduced or absorbed, but not blocked.
Critical hits scored with Arcane damage "silence" enemy targets. (Silenced targets can not cast some spells, such as a Skeletal Summoner or Goatman Shaman resurrecting fallen minions.)
Diablo III Damage Types
Blizzard's @Diablo Twitter feed added some clarification about damage types in posts made in early December 2010.[1]
any change in the range of damage types to include holy, shadow, voodoo or anything else to match the classes? —Scyberdragon
Damage types will likely change some but are currently Physical, Fire, Lightning, Cold, Poison, Disease, Arcane, and Holy. —Diablo
Fairly significant in their difference, but both countered with a single resistance. Damage/resists aren’t design complete though.—Diablo
Whats the difference between poison and disease damage?—WickedBubba
Disease has a damage debuff (both intake and output), and poison has a health debuff (regen/heal). Subject to change of course.—Diablo
Is there much difference between poison and disease? They’re both internal maladies that hurt over a period of time.—Grug
