Marked for Death

Marked for Death is a Hunting  skill in Diablo III.

In-game
The Demon Hunter marks an enemy for a quick death. This makes them suffer increased damage from all attacks for some time. There is no limit to the amount of targets that one may have marked at the same time. Visually, a glowing blood-red rune appears atop the target.

This skill has a very small (0.1 seconds) cooldown (to prevent double-casting).

Runes

 * Contagion: When a marked enemy is killed before the mark has run its full course, it will spread the mark to the closest enemies within  yards. This comes with a full duration refresh. This effect can chain repeatedly.
 * Valley of Death: Marked for Death affects an area on the ground of yard radius instead of an individual target. The duration is reduced to  seconds. Enemies take additional damage while standing in the area, and do not suffer individual debuffs.
 * Grim Reaper: additional  of damage dealt to the marked enemy is also divided evenly among all enemies within yards (excluding the primary target, which takes 15% increased damage anyway). Visually, it displays a dark circle on the ground that follows the target.
 * Mortal Enemy: Every successful hit against the marked enemy by the Demon Hunter generates up to  Hatred for him/her, amount depends on the Proc Coefficient.
 * Death Toll: All allied attackers heal for of their maximum Life (reduced by Proc Coefficient of the skill) every time they land a damaging hit on the marked enemy.

Non-rune enhancements

 * Calamity (Legendary Hand Crossbow): each enemy you hit automatically becomes Marked for Death, benefiting from skill rune, if any.

Passives

 * Perfectionist: reduces Discipline cost by.
 * Custom Engineering: the duration.

Trivia

 * Graphically, Marked for Death uses the very same rune that is applied to character skills.
 * This skill bears some resemblance to the Hunter's Mark ability of Hunter characters in World of Warcraft.
 * Shadow Clones in Realm of Terror will use this skill (with Valley of Death rune) against Demon Hunters.