Blizzard Entertainment expects to ship the long-awaited Warcraft III: The Frozen Throne expansion set worldwide on July 1.

The game has already attracted over 2.5 million pre-orders, and the software has just reached gold status. The initial Warcraft III: Reign of Chaos has sold three million copies.

The expansion set takes players through new adventures in the legendary land, introducing new characters, races, Heroes and single player campaigns. It also offers five neutral Heroes players can hire as they work to accomplish their quests.

Blizzard Entertainment president and co-founder Mike Morhaime said: "When we set out to create the next installment of the Warcraft series, we wanted to increase the strategic gameplay possibilities and depth of the Warcraft universe by introducing a wide array of new Heroes and units specifically designed to enhance each race. We're extremely proud of these new additions, and we look forward to sharing them with players."

UK pricing is currently unavailable. The product costs $35 in the US.