After a rather tumultuous launch, Creative Assembly have been patching Total War: Rome 2 on a weekly basis. And while the updates have typically included free content, it's time for some premium DLC as well.

The "Nomandic Tribes Culture Pack" will add three new playable factions into the game, and will cost $7.99. However, if you download it before October 29, it will be free.

You can pick up the add-on on Steam right now.

According to Creative Assembly's Mike Simpson, the promotion is meant to thank fans. "We are going to continue to work on gameplay feature balancing with our community who have been hugely helpful in feeding back on the game," he said. "Offering this DLC for free for the first week it's on sale is a celebration and a small thank you to them for helping us make this the biggest TW yet."

The three playable factions come with new buildings and building chains, technology tree, campaign objectives and new units. The Massagetae are a fierce nomad tribe with a long history of destroying civilized armies. The Roxolani or 'Bright Alans' are a Scythian-speaking collection of tribes of the Sarmatian people. Finally, in their own eyes, the Royal Scythians are better than everyone else.