Trials of Atlantis will introduce the ability for players to swim to explore the submerged civilization. The expansion reveals that the citizens of Atlantis, foreseeing the demise of their society, built a series of Trials into the ruins of their civilization. The Trials were designed to challenge future cultures that discover and seek to explore the ancient lands. In Trials of Atlantis, the three Realms have each found a hidden portal to the fabled continent. Now it's up to the populations of Hibernia, Midgard and Albion to take on the nine Trials and uncover the mysterious powers amongst the ruins. To succeed, players must master the perilous ocean and confront terrifying monsters, both on land and undersea.

Trials of Atlantis is designed to further challenge high-level players by introducing a Master Level advancement system. As a player moves sequentially through each of the nine Trials, they will achieve a corresponding Master Level. Emphasizing group play, the Trials will have to be surmounted by groups of players journeying through the portal together. Players will be able to travel by boat, explore islands with ruins, swim to submerged dungeons and battle new creatures in underwater caves. Additionally, the expansion will add one new player race per Realm, dozens of new monsters to encounter, as well as new objects and treasures to uncover.

The game's graphics engine will be upgraded to NDL's state-of-the-art Gamebryo, which will enhance ground texturing; improving all landscapes in Dark Age of Camelot as well enabling visually advanced underwater scenes. The expansion will also add a new graphical tree system to make trees and undergrowth more realistic everywhere in the game. Trial of Atlantis will also offer a skinable user interface with more options for customization.

Dark Age of Camelot: Trials of Atlantis requires the original Dark Age of Camelot as well as the Shrouded Isles expansion. This expansion, one of three slated for release this year, will further develop the compelling experience which has already come to define Dark Age of Camelot and its first expansion, Shrouded Isles and will only be available through retail. The other two free expansion packs, including the recently announced housing expansion Foundations, will be made available to all Dark Age of Camelot subscribers.