Alternate Regimental Organisations
The main Imperial Guard list assumes that the force being used is a combined one pulled together from units in the theatre of operations and based around a standard infantry regiment. There are many different kinds of regiment in the Imperial Guard, however, and by selecting any of these Doctrines you will change the nature of your regiment quite fundamentally.
Drop Troops This regiment comes from a world where grav-chute use is commonplace and has been trained in their use for dropping into combat. Any Guard Infantry unit (without a Chimera transport) or Sentinel squadron may Deep Strike if the mission permits. Other units must deploy conventionally. (As an aside, this Doctrine could be rationalised by stating the troops are emerging from Imperial tunnelling vehicles although this would be much rarer.)
May not be combined with Special Equipment: Warrior Weapons.
Grenadiers The regiment comes from a world where the best Imperial Guard recruits are combined into elite formations and receive superior training that is the equal of that provided to Storm Troopers.
The regiment may include 0-3 Storm Trooper squads as Troops. These Storm Troopers may not Deep Strike or Infiltrate.
May not be combined with Special Equipment: Warrior Weapons.
Errata — Chapter Approved: Codex: Imperial Guard Q&A (v1.0): Grenadiers do not need to take an Infantry Platoon first. Their inability to Deep Strike or Infiltrate cannot be bought back with the Drop Troops or Light Infantry Doctrines — Grenadiers are not listed as Guard Infantry and so cannot take any Doctrines at all; their distinctive training is completely built into their profile as printed.
Mechanised The regiment is uniformly mounted in Chimera transport vehicles and specialises in mobile warfare. All Guard Infantry units must take a Chimera transport whether they normally have the option or not.
May not be combined with Special Equipment: Warrior Weapons or Light Infantry.