From Lexicanum

Scouts are the new recruits of a Space Marine chapter who have advanced far enough in their training and biological transformation that have begun to take part in battle with the rest of the Chapter. Partially transformed into Space Marines, they have yet to receive the final implant, the Black Carapace that will mark them as full battle-brothers and allow them to use power armor.

More lightly armed and armoured than full brothers, their role is to range ahead of the main Space Marine force, preparing the way for the main advance by infiltrating enemy lines, sabotaging and gathering intelligence - causing as much chaos and disruption as possible.^{2, 3}

Scouts make up the numbers of the Tenth Company. Each Marine begins his combat life as a Scout. A Scout is rigorously tested in all capacities. Those with psychic potential are given extra training by the chapters Librarium. Those who show an affinity with technology are earmarked for future training as a Techmarine. The role of scout in a space marine chapter is wide and all encompassing. On the field of battle they fulfil many roles. Serving alongside Tactical Squads, taking the fight to the enemy with the assault squads, or providing long-range fire support with the Devastators. In some rare cases, Scouts might also take to the field on Bikes.

Off the battlefield, the scouts train and learn. Taking to heart the information and skill that will one day see them elevated to the rank of a full battle brother. The life of a marine scout, is one of gruelling tasks and painful training. The Genetic alterations will be implanted into them at certain stages of their training. A Scout receives his final implant, the Black Carapace when he is deemed ready to join the Chapter as a full battle brother - the implant marks him as a full brother and allows him to interface with his suit of power armour.

As set out in the Codex Astartes, Scouts are to be organized into the chapters 10th company. However some chapters ignore these teachings. The Space Wolves, for example, do not place their neophytes in the Tenth Company as scouts, instead, Space Wolves who have left or lost their pack for whatever reason are trained as scouts. The Black Templars also have no specific company for scouts. They train their Neophytes by incorparating them in to their squads.

Equipment

Scouts are armoured in a type of carapace armour known as Scout Armour which protects most of their body with rigid plates.

A Scout squad will be equipped according to its designated tactical role. Those who fight alongside Tactical squads will likely be armed with Bolters and Shotguns. Scout squads specializing in close combat would be equipped with Bolt Pistols and close combat weapons. Scouts serving as long range fire support would carry Sniper Rifles and either Missile Launchers or Heavy Bolters.

List of weapons and equipment available to a Space Marine Scout:

• Bolter
• Sniper Rifle
• Shotgun
• Heavy Bolter, which can be used to fire Hellfire Rounds
• Missile Launcher
• Frag Grenades
• Krak Grenades
• Auspex
• Bikes

Images

Ultramarine Biker Scout Squad

Ultramarine Scout Squad

Sources

• ¹:Codex: Space Marines (3rd Edition) p. 11, paragraph 4
• ²:Codex: Space Marines (5th Edition) p. 66
• ³:Codex: Ultramarines

Space Marine Infantry

Command	Master • Captain • Master of Sanctity • Reclusiarch • Epistolary • Codicier • Command Squad • Apothecary • Company Standard Bearer • Company Champion
Standard	Tactical • Assault • Devastator • Scout • Veteran • Tyrannic War Veterans • Honour Guard
Terminators	Terminator Squad • Terminator Assault Squad • Terminator Command Squad