Blizzard Entertainment has announced plans to release an expansion pack for its two-million selling title Warcraft III: Reign of Chaos.

Warcraft III: The Frozen Throne will offer a new sequence of adventures set after the events of the previous title. Features will include new Heroes for each race, new spells, abilities, units and areas to explore. The title will introduce 'Neutral' mercenary Heroes for hire as players battle through levels. The world editor will also be improved - players will be able to create unique cut scenes and voiceovers. New multiplayer maps will also appear.

Evil Warcraft III: Reign of Chaos was simultaneously released for Mac and Windows last year. It puts players in charge of the fate of four successive races in a life or death struggle between good and evil. The title combines strategy gaming with a story-driven plot and a role-playing element as players control a Hero character.

The company has sold eight million copies of the various iterations of its Warcraft series since it shipped the first Warcraft title in 1994.

Beware Orcs Blizzard descrides the plot for the expansion pack as follows: "The evil Lich King Ner'zhul has been imprisoned inside the Icecrown glacier, deep within the arctic continent of Northrend. Although the former Orc Shaman lacks physical form, his soul lives on, forever seeking a means to escape his icy prison."

The Icetown glacier offers powers also sought after by the Dark Elves and the Undead. Players must conquer new enemies to save the world from the forces of darkness once again.

The expansion set is scheduled to ship in summer 2003 and will cost $35 (no UK price is available yet).