You attempt to finish the wounded target off, firing a long range attack dealing 200% weapon damage plus X. Kill Shot can only be used on enemies that have 20% or less health.
You attempt to finish the wounded target off, firing a long range attack dealing 200% weapon damage plus X. Kill Shot can only be used on enemies that have 20% or less health.
BOOM! Headshot!
Kill Shot is a high-level Hunter ability intended for finishing off wounded targets. It is only usable when the target is below 20% health, but has an unusually long range deals an enormous amount of damage. Fully talented it has the longest range (51 yards) of any damaging ability usable in PvP by any class, and in PvE it has the potential to be one of the hardest hitting and highest criting abilities in the game.
Kill Shot deals 200% ranged weapon damage (including contribution from attack power) plus 40% of your attack power plus a fixed number depending on the rank. This makes it scale very well with the hunter's attack power, making the shot deal exceptionally high damage in a raid setting, where the hunter is likely to benefit from multiple buffs that increase attack power, such as Strength of Earth Totem, Battle Shout and Blessing of Kings.
In addition to dealing very high damage, Kill Shot is useful for triggering the Rapid Killing talent to regain mana.
Since it has an unusually long range, Kill Shot is useful for finishing off anyone who gets out of range of your other abilities in both PvE and PvP.
Against target with very high amounts of health, you should use Kill Shot as soon as you can, as the target may have enough health left for you to be able to use Kill Shot multiple times. This is especially true on bosses and if you have the Glyph of Kill Shot to reduce the cooldown.
Edit
2020
Patch 3.2.2 (2009-09-22): Minimum range of 5 yards added. 
