Empire: Total WarEditIn Empire: Total War, most elite infantry are functionally similar to line infantry, with a large number of men per regiment, firing drills, and good morale. As with line infantry, they form the main line of battle, doing much of the killing and dying. They differ in several key aspects, however: they have far better statistics in most categories than their standard line infantry; most elite infantry utilize Platoon Firing instead of Fire by Rank once it's researched; finally, nearly all guards inspire nearby units in a similar manner to that of generals, improving their morale.
All western factions have access to elite infantry. The Ottoman Empire is the only middle eastern faction to have elite infantry, while the Indian factions lack elite infantry of any kind. Native American factions have access to small regiments of infantry technically titled elite infantry, but are functionally very distinct from their western counterparts.
The superb statistics of guards allow them to simply replace line infantry on the battlefield in some situations, but they nearly all have regiment limits.
Napoleon: Total WarEdit
Elite infantry return in Napoleon: Total War, and fill a similar role to their Empire: Total War incarnation: superior line infantry who also serve to inspire nearby units. They are more in line with line infantry with the removal of firing drills.
Unlike Empire: Total War, where nearly all Western factions have access to some elite infantry, a sizable number of factions in Napoleon: Total War lack elite infantry of any kind. Among the playable factions, France has a very substantial pool of elite infantry to draw from; on the other end of the extreme, Austria lacks elite infantry of any kind.
Fall of the SamuraiEditElite infantry return in Fall of the Samurai, functioning in a similar role to their earlier counterparts. In Fall of the Samurai, factions are divided into Imperial, Shogunate, or Republican allegiances; they accordingly have access to Imperial Guard Infantry, Shogunate Guard Infantry, or Republican Guard Infantry respectively, though these units are practically identical in terms of function.
All factions also have the opportunity to trade with the United Kingdom, France, or the United States, giving them access to Royal Marines, Infanterie de marine, and United States Marines respectively. Unlike the natively raised guard regiments listed earlier, these troops do not inspire nearby units, but have even better statistics.