WoW Wrath of the Lich King Rune System

- Runes used to power all Death Knight abilities
- Three Rune types: Blood, Frost, Unholy
- Death Knights carry six Runes at a timeOfficial Site: Death Knight Gameplay
- Once used, a Rune has a ten-second rechargeTen Ton Hammer: Runes and Runic Power Guide
- Using Runes builds up Runic Power
- Death Knights can change runes by runeforging

Describes the WoW Wrath of the Lich King Rune System introduced in the expansion Wrath of the Lich King. Tells how Death Knights can change runes, the three types of runes, and what you need to know to use them.
Death Knights use a special system of runes to power and use their abilities. Though similar to the rage and mana systems, the runic system is a bit more complex.
Runic Power

Some abilities don't require Runes to use, but make use of Runic Power. Runic Power is an energy that builds each time you use a Rune, and is measured in a meter right below the health bar. Runic Power, like a Warrior's Rage, decreases over time if it's not used. Runic Power is often needed for high-power finishing spells. The mechanic works in such a way that you build Runic Power by using a few normal spells, and expending a few Runes. Then, you use that Runic Power built up to unleash a powerful spell like Death Coil, which costs 40 Runic Power.Ten Ton Hammer: Runes and Runic Power Guide
Death Runes

The fourth Rune type isn't officially a Rune type, but a special Rune called a Death Rune. Death Runes are wild card Runes that can be used in place of any of the three main Rune types: Blood, Frost and Unholy.
Death Runes are generated with three abilities. Blood Tap turns a Blood Rune into a Death Rune for 20 seconds, effectively allowing for two uses. Death Rune Mastery, a Blood tree talent, gives you a 30-100% chance (depending on the skill level) to turn one Frost or Unholy Rune into a Death Rune whenever you use the Blood Strike skill. Finally, Blood of the North, a high-level talent, gives you a 20-100% (depending on skill level) chance to turn a Blood Rune into a Death Rune when you use Blood Strike.Ten Ton Hammer: Runes and Runic Power Guide