World of Warcraft: Wrath of the Lich King (also known as WotLK, WLK, or Wrath) was the second expansion in World of Warcraft, following The Burning Crusade. It adds a substantial amount of content to the game world, including the continent of Northrend, home of the titular Lich King, and a new character "hero" class.

Wrath of the Lich King was released in November 2008, selling 2.8 million copies within the first 24 hours of availability. This makes it the fastest selling computer game of all time, beating the record set by the previous World of Warcraft expansion The Burning Crusade, which sold 2.4 million within its first 24 hours.

Northrend

Northrend is a crescent-shaped continent in northern Azeroth. The continent is roughly half the size of the Eastern Kingdoms, but matches Outland in length and width. Although Northrend is known for its snow and ice, developers stated that only parts of the continent were to be frozen over.[9] Northrend features eight zones with content for levels beginning at 68, though players may travel to Northrend at any level.[10] Players arrive by boat (Alliance) or zeppelin (Horde) either at the Howling Fjord or the Borean Tundra zones, each located at opposite ends of the continent. Howling Fjord is home to evil half-giants called the Vrykul who reside in Utgarde Keep, the first dungeon to be described in the expansion. The Dragonblight and Grizzly Hills zones are located in the central-south and south-east parts of the continent respectively. The ursine Furbolgs reside in the forested Grizzly Hills. Dragonblight features the grave-sites of dragons who came to the region to die. Wintergrasp is the first completely player versus player (PvP) zone in World of Warcraft, even on player versus environment (PvE) servers.

The Forsaken and their Queen, Sylvanas Windrunner, have also arrived with a new contagion that they hope will prove to be effective against the undead minions of the Lich King. The Forsaken are seeking vengeance for being subjected to Arthas' magic. They have set up a military base of operations called "Vengeance Landing" and have created a settlement called "New Agamand", both in the Howling Fjord.

The magi of Dalaran have also relocated, along with their city, to Northrend in order to deal with the rising threat of the Blue Dragonflight, led by Malygos the Spell-Weaver, and the Lich King. The city of Dalaran functions as the neutral sanctuary city for the continent, analogous to Shattrath City in Outland. Dalaran is levitating at a great height above the Crystalsong Forest zone but can be accessed by either the ground or by flying mount. The expansion also features more creatures and other enemies, such as the 4 new spirit beasts: Loque'nahak, Gondria, Skoll and Arcturis. It also introduces the vicous dragons called Proto-Dragons [dragons with short arms, huge teeth and large wings], and the gigantic dinosaur King Krush, who stalks the jungles of Sholazar Basin, and is a true challenge for players to catch or defeat, and his hide is green.

According to Blizzard game designers, Arthas Menethil and Ner'zhul, combined as the titular Lich King, are the main focus of the entire expansion.

Death Knight

The Death Knight is the first announced Hero class for World of Warcraft. Death Knights, according to Blizzard developers, are able to sufficiently fill the tank and DPS (damage per second) roles. Death Knights can wear plate armor and wield weapons with rune engravings (enhancements), but they cannot use shields. A Death Knight's summoned pet (ghoul) is temporary and only lasts a short amount of time; however Death Knights can choose to specialize to make the ghoul permanent and give them full control over it.

Players who upgrade their accounts with the Wrath of the Lich King expansion are able to create one level 55 Death Knight per realm (the character number limit still applies), on any realm, once they have a character on the same account of level 55 or higher. Newly created Death Knights begin with a larger set of spells and abilities than new characters of other classes but they start with no talent points and must unlock available talent points for their level by completing quests in the Death Knight starting area in Eastern Plaguelands (called Plaguelands: The Scarlet Enclave). Both the Alliance and Horde factions have access to the class, and Death Knights may be of any race.

Instead of utilizing rage, energy, focus, or mana for combat resource systems, the Death Knight uses a new system; runes, which are displayed under the player portrait, and runic power, which is generated by using runes in other attacks. The Death Knight has two of each type of rune available (blood, unholy, and frost) for use. After a rune is used it enters a (nominally) ten second 'cooldown' period before it can be used again. With specific talents, the Death Knight can also turn their runes into Death Runes, which can be used as any runes type. Additionally, runic power decays over time when the Death Knight is out of combat.

Graphical Improvements

Several enhancements to World of Warcraft's graphics engine were added with the release of Wrath of the Lich King. These include the use of a new shader in areas containing ice, new fire effects, and more realistic shadows and the option to turn down character texture resolution to improve performance.

Level Raise

In World of Warcraft Wrath of the Lich King, there was a level raise from 70, which was introduced in The Burning Crusade, to 80.