In their latest blog entry Creative Assembly has discussed their post-release content plans for Total War: Warhammer, the first game in the trilogy. These include both paid DLCs and free content packs. The former will come in three varieties: Lord Packs, Race Packs, and Campaign Packs. On the other hand, every now and then fans can expect to get new units, magic lores, Legendary Lords, etc. completely free of charge. The developers are also planning to give the players a new playable race near the end of the year for free.
As for the paid DLCs, Lord Packs will each include two Legendary Lords with their own set of quest, generals, and units. A Race Pack will offer a playable race (either a brand new one or one of the existing NPCs) with unique units, heroes and lords, buildings, technology, skill trees, and so on. Finally, Campaign Pack will contain a new challenge campaign focused on a major event from the Warhammer lore, as well as a new race. There are no details so far on which races and events will make it into Total War: Warhammer after the release, and Creative Assembly have asked the fans for feedback on that matter.