Catacombs is the third commercial expansion pack to Dark Age of Camelot (after Shrouded Isles and Trials of Atlantis). The expansion adds a totally new, vast and diverse underground world to the game, in order to put a little more weight on dungeon adventures. There is a new entry point to these 15 catacomb regions in the capital city of each of the three realms. The catacombs themselves are the same for every realm, although they are handled separately so there is no RvR combat.
Other features include the biggest graphics engine update in the history of the game, allowing for more customized characters and faces, "Private Adventuring" which adds instanced dungeons for letting individuals and groups adventure in their own private catacombs, as well as 5 new character classes: the Heretic for Albion, the Vampiir and Bainshee for Hibernia, and finally the Warloks and Valkyries for Midgard.