In the popular fictional universe of Warhammer 40,000 the Space Marine, also called the Adeptus Astartes, has become almost legendary warriors. The Space Marines was created by a group of scientists who hoped to create super soldiers using genetic engineering. In the game the Space Marine is a secret class which is available for players who want to become one. The Space Marine is a character in the popular multiplayer online game Warhammer Online: Age of Reckoning.

In this game, the Space Marine heroes are able to combine their powers to perform different attacks and to use power armour to fight off enemies. These power armour suits are similar to those worn by the Imperial Guard, but the Space Marines uses a variant called Power Armour which gives them additional protection against enemy fire. The Space Marine class of Warhammer 40,000 rules include several different skills. One of these is the ability to change between different space Marine armours, including heavy armour, assault armour and heavy combat armour. The Space Marine's armours are also divided between Tactical and Defensive, and each of these classes can use different power armour.

Each of the three Warhammer Online classes can be played as a solo game or as part of a crew, a group of up to four individuals who are led by a single captain. As a member of a crew, the Space Marine will be controlled by a series of computer programs, giving him the ability to move and fight like an individual marine. A Space Marine hero may also join up with another Space Marine chapter, called a legion, and fight in the name of the Emperor. Some Space Marine chapters are small units of only one hundred soldiers, while others may number in the thousands. There are also Space Marine army formations, which feature specialist units that are especially deadly against certain types of units, such as enemy light tanks.