"The expansion pack featured numerous improvements over the base game. The most notable content included was the addition of the new Fortress faction, composed of Dwarves, with exclusive access to runic magic (which requires resources instead of mana for casting). Three new campaigns, continuing the original game's storyline, were added, along with a selection of standalone scenarios. Fourteen new artifacts, three new creatures and additional campaign heroes were included, as well as the long-anticipated map and campaign editor which was not present in the base game (although it was added in a downloadable patch). Caravans (originally seen in Heroes of Might and Magic IV), simultaneous turns in the multiplayer mode, and a random map generator were also supplied. Finally, the Renegades - a sub-faction composed of seven non-recruitable creature types - were added, featuring prominently in the storyline."
Source: Wikipedia, "Heroes_of_Might_and_Magic_V:_Hammers_of_Fate," available under the CC-BY-SA License.