Would/could a chapter "farm" threats on the worlds they draw aspirants from or base themselves on or would this be highly heretical?

Keep some chaos beasts on one continent (or planet or whatever), some orks on another, some marooned eldar on another, etc. etc.

So, when they want to test their people against a specfic threat, they just send them on a training mission (which those on the mission might not even realize is training) to the appropriate continent (or planet, or whatever).

It sounds good in theory, training worlds with specific threats where the stakes aren't super high (still life or death for those on the mission, but nothing much higher than that)...I think a chapter that tried this would be in pretty big trouble.

Well, it depends on the threat, but I would guess they do leave them be as long as the population doesn't get out of control. If it's some local flora or fauna, and it is part of the ecosystem, it would be probably left alone for testing aspirants.

If it's a xeno organism, then as I said, it would be closely monitored, maybe they have some watch stations or something. I don't know; how long does it take for feral orks to gain some tech? If it's a Feral world, they 'probably' can't develop tech?

Tyranid microorganism? I reckon it would be put down with extreme prejudice unless it is some kind of local strain like Catachan Devil that does not invite swarm to devour the planet.

And as far as Chaos goes, there are multitude of mutated lifeforms that can be seen as natural to that planet in one way or another. Maybe because of the planets past, maybe there is some minor influence of chaos, or the planet is close to some sort of anomaly like Eye of Terror, The Maelstrom etc.

My 2 cents.

Some threats are hard to eradicate (like Orks and tyranids). I could think that they may use a planet that ones was invaded as their base of opperation just to keep the xenos in check. Also some xenos can be contained easier than others. eldar and Tau may try to escape the confines, this could lead to some serious trouble if their kin realises what has happened.

Deathwatch has the Hunting Grounds on Watch fortress Erioch. These are chambers with different environments to fight against xenos from the prisons. (See Rites of Battle)

Space marines prefer to recruit from death worlds, and most of the established marine chapters do this.

I said most, we all know the Ultramarines are "special" so they get a pass.

These death worlds already possess flora, fauna, and other dangers increadibly anethma to human life as part of their basic ecology.

Baal Secundus - Blood Angels: Largely irradiated wasteland of a world filled with rad-mutants (as opposed to chaos mutants), giant fire scorpions capable of killing a man by rending him in two with its giant claws but even more quickly with its deadly venom, areas and pockets of land bathed in radiation so powerful mere moments of exposure without (and some even with) rad-suits result in assured death, among other deadly creatures and hazards.

Fenris - Space Wolves: A planet of everchanging landscape. Half the year the planet is covered in sub-arctic conditions, the other oppresive heat all the while the land and surface is wrent from the gravitational tidal forces of its sun and the changing temperatures of its seasons. Not to mention the more than deadly bears, the sea monsters (including the massive Kraken), and the ever popular Fenrisian wolves.

Some space marine chapters may not recruit from true death worlds but allow or keep the local culture in a violent state, keeping the possibility of death and the need for strength and resiliancy nearly as high as many death worlds.

Chogoris - White Scars: A verdant world with many different climes, where the White Scars keep the indigeounous warring tribes in a constant state of warfare. Picking out the strongest of the planets warriors for recruitment.

As others have pointed out, space marine recruitment generally occurs from Death Worlds where the fllora, fauna, political climate, or evniroment is already hostile to life. Of course personally i'm always suprised a few more don't recruit from fortress worlds as the Ultramarines do, but that's a stylistic choice that's evidently be made, maybe it's easier to part with a Death World then a fortress world.

While they make no attempt to civilize the world they don't import xenos species. As others have said once you get orks or tyranids on the planet the chances of ever being completely rid of them are kind of difficult. Orks at least you can kill them all and resettle while keeping on the watch for new bands of greenskins. If a tyranid force ever gets out of hand the hive fleet stops by and destroys all life on the planet.

Passing over Fortress worlds for recruitment is probably more to due with the kinds of worlds Space Marines typically wield dominion over, and less to do with their personal tastes.

The Imperial Fists (and perhaps others) recruit from the underhive gangs of Necromunda afterall, and it is hardly a civilizard place. They earned this right (I think) by saving the world from some past aggressor (or a traitor's attempt to secede, whatever). Likewise the Black Templars build their keeps on pretty much any world they fight on, if it strikes their fancy. In both cases it's basically victory spoils.

One could theorize that Fortress worlds are generally a more tricky example, as the myriad of local power blocs (not just the governor, but also the Imperial Guard and Navy) might be against the Space Marines drawing on their good stock, and otherwise mucking about in their affairs. The Ultramarines are more of an exception not because they're "the Ultramarines", and more because they are the rulers of the entire realm of Ultramar, which includes a myriad of world types within their sphere.

I don't think it really would be needed from an Astartes point of view.

Most specific training for Astartes seems to come in the form of hypno-training. Most of the fluff seems to indicate(to me anyway) that training is more about team buillding and general conditioning than skill building. For recruits, training is more for culling out those not fit to be Astartes and indoctrination into the brotherhood. For that purpose, a harsh world is what's needed. Even Macragge, while not a death world, is a world of extremely tough terrain with plenty that would kill a normal man.

Also, why waste resources farming? In the grim dark future, there is only war. The only common xenos that can't be readily tracked down for "on the job training" would be Eldar (either sort), and you probably couldn't farm them as you describe. For Chaos? I would think that they would be so anathema to Astartes that anyone even suggesting some sort of farming of chaos creatures, even if it were possible, would be turned into a servitor in short order.

Just as an aside.

Well, hypno training is most likely used for academics, biology usage (sus-an membrane), technical primers (basics of driving a rhino), and textbook tactics. Combat abilities and hands on tactic training would come from actual real life training. Actually beating up on something or outflanking an enemy, etc. As many of these skills must actually be performed to be learned.

Saying you can hypnotrain driving but not combat is spliting a fine hair, it all works by handwavium. Now there is a lot to be said for muscle memory but if that's what your going for any skill with a physical component including driving a Rhino will likely involve actual real world training. Just to split a grox hair.

I remember some sources indicating that Temple Assassins' inhuman reflexes are at least partially implemented through hypno-conditioning. Since Astartes utilize this technique as well, it's possible that they also imprint basic combat knowledge and reflexes to speed up the lengthy training procedure. Then, some Chapters might not be so keen to use such techniques, believing all combat experience must be earned the hard way - Black Templars come to mind in this regard.

Back to OP's question, I don't think any Chapter would willingly cultivate a Terminus-level threat on their own recruitment worlds. Between the risk of corrupting the populace, the possibility of the threat escalating to such a degree that nothing short of Exterminatus can prevent it, and last but not least, the prospect of the Holy Ordos taking action, I just don't see it happening.

Also, while it would be a great feat, no Chapter expects their potential recruits to be able to take on such threats. The way Space Marines see it, they're created specifically to deal with the worst stuff galaxy throws at humankind, and to expect the same from ill-equipped, non-augmented candidates is unproductive, to say it gently.

To knowingly allow Chaos worship on your recruitment worlds is the highest blasphemy, and any Chapter who'd do so would get branded Excommunicate Traitoris - and that's assuming it didn't go renegade earlier from possible closet Heretics getting inducted into the Chapter Cult and sowing corruption among the brethren.

The way they do it is cultivate low level threats such as various predatory species. This way they can ensure a proper Darwinian environment for potential recruits without risking the loss of the whole planet in the process.

jbuck said:

No, they wouldn't tolerate xenos as threats. But vermin-level (aka non-sentient beings) threat are quite common. Crimson Fists, for example, need the continued existence of Barb Dragons on Blackwater o conduct their annual Rite of the Dragon.

Alex