Arcanum of Rapidity

The Arcanum of Rapidity is a enchanted gem that will add a haste effect to either a head or leg item. This effect will not stack with other enchantments on the item.

The Arcanum of Rapidity is a quest reward from the quest Libram of Rapidity which starts with Lorekeeper Lydros in Dire Maul. To complete the quest, you must turn the following items:

• 1x Libram of Rapidity
• 1x Pristine Black Diamond
• 2x Large Brilliant Shard
• 2x Blood of Heroes

• The Savage Guard - Arcanum of Rapidity

• The Arcanum used to be needed for the special class-specific Zul'Gurub enchantments. However, the requirement was removed in Patch 1.11.
• The quest to get all Arcanums are repeatable.
• Attack speed increases do stack with each other, you can get two librams, a counterweight and haste to gloves enchant, and they all stack.
• "Haste rating" is now used instead of a straight percentage buff. According to Blizzard, items converted to the new rating system have no direct changes in their effects.