There are many worlds in the Imperium where the horse is still widely used. Not all of these are feral or mediaeval worlds. Some, like Avar III, have a privileged class which spends a great deal of time on horseback, whiling away their leisured hours with equestrian sports and hunting. Others, like New Klondike, have rough terrain and low native fuel resources, which make the horse a more practical form of transport than a motorized vehicle.

Even among the feral and mediaeval worlds, there is an enormous range of cultural types which may give rise to elite cavalry forces. There are the outriders of nomadic herding cultures, as on Dolgan IV and Temujin's World; there are mounted raiders such as the Horse Lodges of Cochise and the kozaki of Novgorod; and there are formalized horse-warrior aristocracies such as the Holy Orders of Avalon and the badokai of Epsilon Tokugawa III.

Common to all these planets with diverse cultures and customs is their equestrian elite, a warrior class that has accumulated generations of experience and tactical wisdom in the use of cavalry on the battlefield. These horse-warriors are always subject to close inspection by the Imperium, and they are frequently drafted by the Imperial Guard when a regiment is raised from their home world. On the move advanced worlds, cavalry units are always incorporated into the Planetary Defense Force and it is from this that the Guard recruits. On some of the more primitive worlds, the Guard recruits directly from tribes and clans of horse warriors - legends and great epics are born at these times, and tales of undying heroes joining the Star Riders to battle on the Fields of the Night are commonplace.

During the long period of transit to thew regiment's posting, Rough Riders are trained in the use of Imperial Guard weapons and tactics, just like their infantry counterparts. They are also trained in the use of the imperial Guard hunting lance with its shaped-explosive head, and in advanced cavalry techniques. Imperial Guard transit ships are large enough to provide extensive training areas even for mounted units, as well as the stabling and accommodation needed for the horses and their riders.

It is not only the riders who learn new skills - their mounts are given biochem treatment and extensive training to prepare them for modem battlefield conditions. Once they arrive at the combat zone, months or years after leaving the familiar terrain of their home world, Rough Rider horses will not panic under fire, or shy away from unusual sights and smells such as Orks and Dreadnoughts.

Over the cratered terrain of a battlefield that has suffered a heavy bombardment, horses have often proved superior to motorbikes or armoured vehicles. A platoon of skilled Rough Riders can be an effective assault and skirmishing force, able to move rapidly over the broken ground, and equally able to climb steep slopes as to gallop along narrow ravines. And when they finally confront the enemy, Rough Riders can charge into the opposing lines with their explosive lances, quickly changing to chainswords and laspistols after the initial onslaught.

Like other members of the Imperial Guard, Rough Riders retain many of the customs of their home worlds. The use of tattoos, ritual scarring, unofficial uniforms and tribal symbols is widespread amongst the Riders, and many platoons retain the pennants of their old tribe or unit, flying them from 'their lances below an official Guard banner. The horses of the Rough Riders are freeze-marked on the rump with Imperial Guard insignia: the freezing brand painlessly destroys the pigmentation of the hair and leaves a permanent mark in the shape of a stylized eagle surrounding the head of a horse. Many horses also retain the brands and markings they carried before recruitment to the Guard; among some of the Riders drawn from more barbaric cultures it is even the custom to ritually scar or tattoo the mount along with its rider, leaving raised welts or colourful markings to commemorate the platoon's most heroic actions.

In many regiments, the officers of the Rough Riders are drawn from a long-established ruling elite. Despite their recruitment into the Guard and their official ranks, these nobles are regarded by both themselves and the other troops of the regiment as natural leaders, able to command

the service and respect of their home world inferiors beyond the call of duty. It is common for these noble Riders to pass their leisure time in the hunt, using infantrymen as beaters to flush out the exotic wildlife of the planets on which they are stationed. Their training and the use of explosive lances hardly makes for a fair competition between hunter and hunted, and it is usually considered poor sportsmanship to arm the lance unless the prey is especially large and ferocious.

Other customs are upheld even on the battlefield, and the Guard may condone unusual tactics by Rough Rider platoons if the skills of their home worlds are shown to be effective against the Imperium's foes. The most common Rough Rider tactic is to charge the enemy with explosive lances, switching to chainswords and laspistols once the platoon have made their initial breakthrough. Some Rough Riders, especially those who were accustomed to fighting with cavalry sabers, prefer to arm themselves with chainswords, slashing fiercely to either side as they contact the enemy. Other units tend to stand off, firing at their opponents with lasguns, often galloping past and making themselves hard targets to hit. Whatever their tactics, the mobility and speed of Rough Riders always make them a potent force on the battlefield, able to spearhead an attack as easily as run a flanking maneuver, thus keeping enemy commanders on their toes watching for unexpected attacks by the mounted Guardsmen.