The pre-release update for the upcoming Warlords of Draenor expansion pack is set to roll out in World of Warcraft this week, Blizzard has announced.

In the US, that means tomorrow, while EU players will get the update on Wednesday.

As part of the update, a new world event called the Iron Horde will be made available. Players are charged with stopping the horde as it surges through a portal and into Azeroth.

The patch is intended to overhaul many of the games more dated aspects, updating older character models and improving the Dungeon Finder so it has more functionality. Another set of upgrades are being made to the storage systems.

Certain skills will also be removed from the game, with the patch also getting an updated UI.

The Warlords of Draenor expansion is set for release on November 13, and will release simultaneously worldwide.