The game has launched in Australia and New Zealand and the UK and is set for a November 3 release.
It was developed by the company behind The Witcher 3 and The Witcher: Wild Hunt.
There will also be a free-download option for those who buy through Steam.
The game’s $39.99 US price includes the game’s two multiplayer modes, and an all-new game mode, called ‘The Battle of Ashford’.
In ‘The Clash of Kings’, you and up to three friends battle against a massive army of enemies.
The map will be split into four large areas, and players will battle over a number of different areas.
There are no specific release dates or release dates for the free-content, but it was confirmed by the studio that the game will be out on December 9.
The Battle of Kings is an expansion pack to The Clash of Kingdoms, which comes out on Steam on November 14.
The title features new maps and new heroes and spells.