Mana Tap

Mana Tap was a blood elf racial ability used in combination with Arcane Torrent.

This ability was removed in patch 3.0.2, partly due to lore reasons. In the closing hours of Burning Crusade the Sunwell was reignited and began to feed the sin'dorei addiction for magic again, thus removing the need to tap mana from other creatures. The practical reason however was that while it had its uses, such as a ranged cornerpulling tool for blood elf paladins, the mechanic to maintain three charges to release arcane torrent was deemed too much of a hassle, especially in raids and other content that required more attention to other functions.

It is still referenced in the flirt emotes done by female blood elves. It is also still used by some blood elf NPCs in Outland.

Role in the lore
Mana tap is unique in that it is (or was) one of the few racials not only directly referenced in the lore, but a large part of it. Via Illidan Stormrage, Kael'thas Sunstrider was able to learn a formidable technique by which to sate the elves' magical addiction: the process of forcibly taking arcane magic from external sources. A servant of his, Rommath, went on to spread these teachings back home in Quel'Thalas, allowing the general sin'dorei populace (of which we the players belong to) to better deal with the pangs of addiction. Prior to its removal in Patch 3.0.2, instruction in its usage (mana tapping the crazed mana wyrms around the isle) was among the first things taught to new blood elf players.

Reckless overuse of the technique led to the birth of the Wretched, a group of physically warped magical addicts who showed neither restraint nor sensibility in their mana tapping.

The racial's removal also ties directly into the lore, as with the revival of the Sunwell, there is no longer any need for blood elves to continually sustain themselves with energies from any other source than the well.

In the lore, even non-magi ordinary blood elves like Valeera Sanguinar are able to use Mana Tap for potent semi-offensive purposes, such as Valeera critically weakening Broll Bearmantle during his arena fight; absorbing magical energies from the naga during their confrontation at sea; and preventing several assassins from slaying Varian Wrynn after they reached the Eastern Kingdoms.

Tips and tactics

 * Mana Tap breaks Polymorph, Sap, and Freezing Trap as the mana drain counts as an attack.
 * Since Mana Tap costs zero mana, it's good to use mana tap as quickly as possible, remembering that arcane energy stacks up to 3 times.
 * An enemy that has run out of mana will have any remaining mana drained up to the maximum of the ability.
 * Doesn't work on enemies with no mana bar.
 * Can be used to pull mobs efficiently if you lack any other means.
 * Mana tap activates the global cooldown.
 * For a long while, the racial was a retribution paladin's only source of ranged attack, barring judgement.

Trivia
In Heroes of the Storm, Mana Tap is one of the Talent choices for Kael'thas Sunstrider.