Avernum 6

Avernum is the current stable release of a "demo ware" role-playing game series developed by Jeff Vogel. The series takes place in an underground world called Avernum, in which its occupants, the Aventis, are in a constant power struggle against the inhabitants who live above ground, who are known among the underground dwellers as the Empire.

Much like other RPGs, players may choose which race to play the game’s missions. Each mission is entirely dependent on the historical background of the chosen race. Three significant races are playable in the game: the humans, which are the primary race in the game, the Slithzerikai, and the Nehalem.
Other races can be encountered by the player, such as the Vantaa and other exotic extra terrestrial species that have burrowed deeper underground. However, these minor races are not playable.
As the game is considered demo ware, the program allows users to complete missions along the first few levels if the game. However, as the game progresses deeper into difficult levels, a registration is required to unlock the levels. Registration is possible by purchasing a key that unlocks the premium levels.

As several iterations of the game exists, Avernum serves as the sixth installment in the entire series and the third in the “Second Trilogy” of the series. The in-game story in the sixth version deals with disasters that have struck Avernum since the previous version.