Deathwatch - Core Rulebook, including a pre-written adventure ( ISBN 978-1589947788).
Responsible for maintaining all equipment within the Deathwatch, including Dreadnoughts, powered armour, Terminator armor, and weapons.
Techmarine - Space Marine who is also a Tech-Priest of the Adeptus Mechanicus and thus can communicate with the Machine Spirits of the Imperium.
Specifically hones squad leadership abilities and is normally the Marine in charge.
Tactical Marine - The Space Marine "leaders".
This is normally an individual who would qualify as a Sanctioned Psyker and also meets the indoctrination requirements for a specific Marine chapter. Normally armed with a weapon like a lascannon or heavy bolter.
Devastator Marine - Heavy weapons expert.
Assault Marine - Close combat expert usually equipped with a jump pack, close-range and melee weapons.
Has a stim glove that allows him to distribute pain killers and extract gene seeds from fallen Space Marines.
Apothecary - Combat medic of Space Marine forces.
In most campaigns the Squad Leader is either chosen by one of the players or is an NPC controlled by the GM. In Deathwatch, Space Marines are divided into groups based upon their individual abilities. These individuals are recruited from their native Chapters (fighting units of approximately 1,000 men) to serve as a military arm of the Inquisition, against particularly dangerous heretics and alien lifeforms. In Deathwatch, players take the role of surgically modified super humans known as Space Marines. The player characters are loyalist Space Marines.