The next expansion for Blizzards competitive card battler Hearthstone will take players to the Mean Streets of Gadgetzan. Blizzard announced the expansion on stage at its annual Blizzcon event, giving a bit of background to the expansion, as well as showing some of the new cards coming to players.

Anyone familiar with World of Warcraft will know the desert Goblin town of Gadgetzan, but the version of Gadgetzan serving as the setting for the game's latest expansion has grown from a small port town to a bustling city. Alongside that growth have come some unsavory characters who populate the dark alleys and streets of the city, all of which influence the dark theme and types of cards you'll see in the expansion.

The biggest addition in Mean Streets of Gadgetzan is that of the tri-class card. As opposed to class-specific and neutral cards that have populated the game thus far, tri-class cards are playable in decks for three classes.

The expansion is expected to arrive in December, and we should learn more as we approach launch.