In the table-top strategy game, Warhammer 40,000, the Imperial Guard is easily the largest fighting force of the Imperium. It is comprised of billions of soldiers from thousands of different regiments, supported by a dazzling array of light and heavy armored vehicles. They are usually the first Imperial fighting force to respond to any major invasion or uprising if the planet's PDF (Planetary Defense Force) fails to suppress it.

The Imperial Guard are much more widespread than the Space Marines. Imperial Guard are also much more expendable; the loss of a hundred Imperial Guardsmen would still not equal the loss of one Space Marine. Although in actual game terms, to balance the game, Imperial Guard are able to fight Space Marine armies with a reasonable chance of victory.

Imperial Guard, while weak individually, rely on numbers to win and their superior tanks. Even a small Imperial Guard division is likely to have a full compliment of armored fighting vehicles. Imperial Guard, while not as bad as Tau, are notorious for poor close combat abilities.

The Imperial Guard also have a number of specialists at their disposal. They have access to Stormtroopers, elite Imperial Guardsmen who have been issued better weapons and stronger armor.

Though general-purpose Imperial Guardsmen are weak in close combat, with the help of specialists such as Ogryns (brute-like Ogre creatures), their stength in close quarters is boosted. Also, different Imperial Guard regiments have special rules like Ambush to help stun the enemy for a headstart in the fighting.