Each standard Codex Chapter consists of ten companies. Each of these companies is notionally one hundred men strong.
The 1st Company is made up of the veterans of the chapter. These include Veteran Squads, Terminator Squads and Terminator Assault Squads. Support for the first company is Land Raiders and Dreadnoughts.
The 2nd, 3rd, 4th and 5th Companies are known as Battle Companies and are split into six Tactical Squads, two Assault Squads and two Devastator Squads. The Assault Squads can be deployed as Bike Squadrons or Land Speeder Squadrons and often use Rhino or Razorback transports. Each of the main Battle Companies have four Dreadnoughts available to them.
The 6th, 7th, 8th and 9th Companies are known as Reserve Companies. The 6th and 7th Companies are made up entirely of Tactical Squads, the 8th of Assault Squads and the 9th of Devastator Squads. They also make use of Rhinos or Razorback transports, though Dreadnoughts are usually only found in the 9th company. The 6th can also be deployed entirely on Bikes and the 7th on Land Speeders. The 8th can use either.
The 10th Company, or Scout Company, consists entirely of Scouts and is often not one hundred strong as a steady supply of recruits is not possible. They are the most lightly armoured and usually used as a reconnaissance force. They are sometimes mounted on Bikes but do not use Rhino or Razorback transports.
- The Great Companies of the Space Wolves
- The Clans of the Iron Hands
- The Brotherhoods of the Grey Knights
- The Brotherhoods of the White Scars