Game developer Blizzard has announced that the "World of Warcraft' online multiplayer game will go back to the legendary battle between the Alliance and the Horde in its upcoming expansion called "Battle for Azeroth."

The company made the announcement during the annual BlizzCon, which is a celebration of the company's rich lineup of gaming franchises. The new expansion is expected to add to the level cap and introduce new areas to the game.

Thematically, the expansion pack will bring into focus the battle between the Alliance and the Horde, the two factions that have been warring since the early days of the popular franchise.

The expansion will send both factions to new territories to recruit new allies who will fight for their cause. Alliance players will be sent to Kul Tiras, the island were Jaina Proudmoore was born, while the Horde will venture to islands of Zandalar.

"Battle for Azeroth" comes with two new game modes, the Islands system and the Warfronts system. Islands mode is designed for a small teams of three players who will compete to clear the island to take home resources for their faction. In this mode, a player-controlled team can battle against another player-controlled team, or against an artificial intelligence (AI)-controlled team.

The Warfront system places 20 players to a cooperative instance, where they need to work together to collect resources or to besiege enemy territories.

In "Battle for Azeroth," players will get a new legendary neck piece called Heart of Azeroth. The equipment can be customized depending on the players' build, and with it, players can unlock new powers and traits.

Blizzard has not revealed an exact date of release for "Battle for Azeroth." Historically, "World of Warcraft" releases a new expansion after around 18 to 24 months. This puts the release date of "Battle for Azeroth" at some time in the middle of 2018.