Space Marines - Exposure Trial: Few worlds of the Imperium of Man are free from adversity and these rare exceptions are either the holdings of wealthy mercantile combines or pleasure retreats for retired, high-level Imperial servants or the local sector nobility, entirely inaccessible to the vast bulk of Mankind. Most of the Emperor's subjects live on worlds that are dangerous in some manner.Long-settled planets are riven by pollution, the toxic waste of thousands of Terran years of industry seeping into the very bedrock and raining from the skies in a constant downpour. Other worlds are heavily irradiated, by the processes of industry or by the effects of local celestial phenomena. Younger worlds where Mankind's dominion is not yet fully established, are often host to all manner of hostile lifeforms, including predatory beasts, carnivorous plants and virulent microbes.Plenty of worlds feature environments that are inimical to life, yet due to some natural resource or the world's strategic value, Humans eke out an existence there nonetheless. Such environments range from sub-zero ice wastes, impenetrable swamps and arid deserts to exotic Death World jungles, methane sumps and hydrocarbon oceans.In an Exposure Trial, the aspirant must go out into such an environment and simply survive for a set period of time. If he is a native of such a hellish place, the aspirant will have some knowledge of how to survive, yet is shorn of all aid and divested of all but the most basic of survival equipment.Communities living in the midst of a Death World jungle, for example, rely on total and constant cooperation just to go on exisitng another day and none are ever out of the sight of another. An Exposure Trial in such a place would force the aspirant to go out into the jungle alone and face the terrors of the wild with only himself to rely upon for the first time in his life.Some Exposure Trials test the aspirant's fortitude in a specific environment. Such Trials carried out in an icy waste could involve the aspirant travelling from one point to another, with countless hundreds of kilometres of trackless snow-blasted plains separating the two. Other aspirants might have to cross an entire continent of irradiated ash dunes, traverse an impassable mountain range, swim a predator-infested ocean or a hundred other such challenges.One particularly inventive variation of the Exposure Trial is one in which the aspirant is taken from his own environment and transplanted into an entirely unfamiliar one. A Feral World savage might be deposited in a hive city, for example, or a Hive Worlder in a predator-infested Death World jungle. Many Exposure Trials are impossible to complete, entailing the aspirant simply staying alive as long as possible.Those who face the impossible without faltering and who survive long past the point they should have perished are recovered by the Chapter's Apothecaries, often having succumbed but not yet died, and revived, having been judged worthy of becoming an Astartes neophyte.Amongst other types of Trial, the Ultramarines make extensive use of the Exposure Trial. In fact, some of the warrior elite of the Realm of Ultramar are known to cast newborn infants into the wilderness in order to test their resilience. The Space Wolves use similar methods, as do many other Chapters.