Shadow Word: Death

Shadow Word: Death is a priest Shadow Word - a Shadow-based direct damage spell, and deals equal damage to the caster if the target is not slain by the cast. When cast upon targets at or below 25% health, its damage is tripled - for the target and the caster. It is learned at level 32 for.

The self-harm effect limits usage, though it may be used on any potential target - for a price. Masochistic Shadow priests in particular may well be willing to pay that price, drawing mana from their own suffering.

Talent Improvements
Shadow tree talents:
 * Shadow Power (Shadow tree specialisation) increases the damage done by 15% and critical damage done by 100%.
 * Shadowform increases the damage done by 15%, and reduces the damage taken from the backlash by 15%.
 * Masochism: when you take damage from your Shadow Word: Death you instantly gain 5/10% of your total mana. This makes casting SW:D upon a non-critical target (thus ensuring that you will take damage) an excellent technique for restoring your mana, potentially restoring 10% of your mana every 10 seconds, 10 times the benefit gained from Vampiric Touch.
 * Pain and Suffering reduces damage (backlash) you take from your own SW: Death by 20/40%.

Discipline tree talents:
 * Twin Disciplines increases the damage done by 2/4/6%
 * Mental Agility reduces the mana cost by 4/7/10%.
 * Archangel: Consumes your Dark Evangelism, causing Dark Archangel: Instantly restores 5% of your total mana and increases the damage done by your Mind Flay, Mind Spike, Mind Blast and Shadow Word: Death 4% for each stack (up to 5). Lasts for 18 sec. 90 sec cooldown.

It is possible for Shadow priests to spec all of the above talents in order to improve this spell to its maximum.

Glyph Improvements

 * Glyph of Shadow Word: Death: If your Shadow Word: Death fails to kill the target at or below 25% health, your Shadow Word: Death's cooldown is instantly reset. This effect cannot occur more often than once every 6 sec.
 * Glyph of Spirit Tap: When you kill a target with your Shadow Word: Death that yields experience or honor, you receive 12% of your total mana over 12 sec.

Tips & tactics

 * Mind Blast is ultimately more damaging than Shadow Word: Death at top level, but Shadow Word: Death is far more mana efficient.
 * Shadow Word: Death can be used by healing Priests to trigger a Prayer of Mending that has landed on themselves, thus preventing the Priest from having to fight to gain aggro, waste a Fade, and possibly die.
 * Be careful of using Shadow Word: Death in certain fights (The Curator in Karazhan, for example, during his evocation period; the 300% damage increase will more than likely kill any Priest, especially in the event of an unlucky crit).
 * The backlash from Shadow Word: Death can be used to break Polymorph effects if used shortly before the spell finishes. Details on how to use Shadow Word: Death to break Polymorph and Video Demonstration.
 * Don't feel restricted to only using this spell on those with low life. Priests (Shadow Priests, in particular) have a large amount of passive healing thanks to Vampiric Embrace and Vampiric Touch, and can absorb the backlash with their shield.  Watch your health, however.
 * Try to be careful when using this against a Warrior with a shield and Spell Reflection. A reflected Shadow Word: Death is considerably harmful to yourself, and in some cases fatal.