I am puting together a game for a friend of mine, who always GMs and never gets to be just a player. I have just started working on it and have a basic plot down, but i could use some help on flushing it out a bit.

Here is a very brief overview of the plot

It is going to be a solo game where he is going to play a Gaurdsmen and will take place on a planet (yet to be named) where to only thing of any value to the imperium is a very rich Adamantium mine and it is currently under a large attack by Ocrs. My players character is going to be placed into the Imperial Gaurd on planet in an attempt to uncover suspected cult activity. The Cult of the Horned Darkness is going to have gotten a foot hold in the upper ranks for the Guard Stationed on planet and are using the mine as a location for profain rites and sacrifices.

Note that this is just a VERY basic overfew of what i have come up with so far, no need to bore you with the little details...and my player may be reading. I am watching you J!!

What i could use help with is, what would the structure of a large Imperial Gaurd garrison be?

What would be the command structer?

How Many regiments, how many gaurdsmen per regiment?

How many Commisonars, Clergymen, Tech-Priests ect ect, per regiment?

The Terrain around the base will be rugged mountian terrain with little to no vegitaion and wildlife, so what kind of Mechinized units would you recomend. I cant see tanks being on any use, but heavy artilery and air support would be useful.

Am i forgeting anything?

Any advise would be greatly appreciated.

The real trick to answering the particulars about the IG unit composition and TOE is you have not specified which IG unit this is. Obviously there is a massive difference from organization, combat doctrine, wargear, fighting formations, traditions and so on between every Imperial Guard unit throughout the galaxy. Plus there us the slight matter of "local conditions leading to variations on abovementioned traditions to facilitate story development".

First question to ask yourself: Is this a true IG regiment? If yes, where are they from? If not, are they PDF troops, House Troops in service to some local noble, mercenaries, local militiamen?

If they are actual honest-to-Emperator Imperial Guard then some of this is already handled for you. The only true commonality for all Imperial Guard units is service to the Emperor, as even the ubiquitous lasgun is sometimes replaced by autoguns, shotguns, bolt-action rifles or even stranger weapons as training, local traditions and supply demand.

Cadians (Shock Troops/Kasrkin) are highly trained and disciplined professional soldiers known for their elite infantry, top-grade wargear and clever battle-tactics.

Catachans are close-knit warrior bands with barely adequate discipline, very non-uniform battledress, clannish to outsiders, cheerfully willing to take on stupidly-lethal risks and absolutely viscious close-in fighters. They have no special name for Catachan IG regiments, but elite squads are called "Catachan Devils" after a particularly nasty critter from their homeworld.

Talarns (Desert Raiders) are masters of hit-and-run mobile warfare. They utilize a mix of cavalry, armour and infantry in swift mobile strikes.

Armageddon IG (Steel Legion) are from a toxic hiveworld with an ork problem. They specialize in mechanized warfare and every soldier and vehicle is fully enclosed and sealed against hostile environments.

Vostroyans (Firstborn) are stubborn, traditionbound and disciplined. By ancient tradition dating back to the time of the Horus Heresy the firstborn sons of all Vostroyan families (no exceptions!) are inducted into the Guard. They specialize in city fighting and are quite comfortable in the cold.

Elysians (Drop Troops) specialize in airborne assault, using rope lines or grav-chutes to swiftly enter battle from the troop bays of Valkyrie gunships. They favour lascarbines over larger lasguns and specialist weapons (plasmagun, meltagun, flamer, grenade launcher) over heavy weapons.

Scintilla PDF (Army of the Scintillan Protectorate) or Brontian IG (Longknives) have scattered bits of info through the various DH books and add a Calixis Sector local option.

There are many, many more IG units out there to choose from. One interesting option might be for the troops to be Tech Guard (Skitarii). The best known "private army" in Calixis Sector is probably the "Royal Scourges" in direct service to the Queen of Sepherus Secundis, though they mostly keep busy by brutalizing anything that might get too uppity or looking at a noble the wrong way on their homeworld.

Hoping this helps you out some.

Thanks for the reply ZillaPrime, i apprecaite your help

I have actually already have 3 IG units in mind, 2 of which i am deffienatly going to use, one i am on the fence. I am begining to think that 3 regiments in one location may become too much for me to easly handle. I deffently what 2 very different regiments on planet so i can have a rivalry between the 2. That way if i feel the story is progressing to quickly i can have some petty infighting crop up that will distract my player.

My main issue is that i have never played the table top game, so i am unfamilar with the actual structure and numbers of a regiment, but i think i am going to just make it up, no one said my military has to be the same as anyone elses. While there will be one person in charge of the over all defences, I am deffentaly going to have a high ranking officer, a Commisar, and Cleric for each regiment. I am looking forward to having each pull my player in different directions.