(Note: It is hardly possible that all giants are of the same species, but the argument might be made about the so-called "earth giants," and even that (at least some) earth giants represent a race (or several races) of /Homo sapiens/. It appears that a common evolutionary adaptation to the availability of sorcerous power in the Black Steel world is to take advantage of that power to support a body too large to function on the basis of physical strength alone, leading to the likes of giant insects, giant lizards ... and apparently, giant human beings. The number of giants that evolved naturally, and the number that evolved thanks to the interference of -- or were created outright by -- sentient beings wielding powerful sorceries, is difficult to estimate, particularly if the tales are true of certain giants who themselves consciously weaving sorcery. (The sorcerous adaptations that allow creatures to survive at enormous size are unconscious in nature -- giant insects are not sentient as a rule -- and may even occur on the cellular level.) If a race of, say, giant elves consciously guided its own evolution via woven magics, would that represent natural development, sorcerous interference, or both?)
Giants come in various sizes (from very big to just enormous) and self-appointed giant killers tend to classify them by size, sometimes crudely, as in, "We've got a seventeen footer out by Barleymoor," other times by misappropriating more useful descriptive names. When a "woodland giant" is reported descending upon a town out of barren mountains, it is usually for this reason, though of course, being sentient beings, giants of any classification do not always live up to their names.
Most giants familiar to Black Steel personnel, and apparently the most common giants in the world by a wide margin, are those known collectively as "earth giants" -- those whose appearance, behavior, and abilities are essentially in line with those of humans, goblins, and (for the sake of argument at least) elves, apart from their vast size. Such giants are by and large reputed to be slow-witted, clumsy creatures with nasty mean streaks, and the reputation is not entirely unearned, at least in the experience of Black Steel personnel. Moreover, it appears that the larger giants are likewise on the whole less agile, both physically and mentally. Thus, though legends of magic-wielding earth giants do exist, it seems unlikely, especially among the largest of giants, that they are actually capable of mastering the intricacies of sorcerous power -- and indeed, Black Steel personnel have never encountered a spell-wielding earth giant. The issue of mean-spiritedness is another matter however, and Osiavia has posited that it is primarily related to hunger -- more common among larger giants simply because they have to work harder just to feed their enormous bodies -- and indeed, the giants with which Black Steel personnel have direct dealings always seem more relaxed and personable after a good, hearty meal (though this could perhaps be said of almost anybody). It is imaginably possible that even their intellectual limitations arise from the same source -- the need to feed such massive bodies certainly leaves little time for contemplation, study, or other intellectual pursuits. It would be an interesting experiment to attempt to raise giant children from birth among human peers, providing for their feeding and other needs, but the expense would be enormous, to say nothing of the logistics of the thing, or the difficulty of acquiring a meaningful number of newborn giant children.
Presumably for reasons related to the availability of food and other resources, the largest giants are also the least numerous, and the least likely to form large communities. Those that are small enough to do so successfully without exhausting local food supplies faster than they can move to new localities typically gather in tribes reminiscent of goblinoid and primitive human communities. Such tribal giants are most commonly known as ogres, and are often of less than three meters in height; the smallest among them can sometimes pass as unusually large, brawny humans or goblins if properly attired, among those unable to see into their magical nature. (Younger giants can sometimes pass as full-grown members of smaller races as well, but this is rare, as -- for instance -- a giant child usually looks like an oversized child rather than a human teenager.) Ogres themselves appear on the whole to regard the distinction between themselves and humans or goblins as one essentially of family and upbringing rather than of race or species. There has never to Black Steel knowledge been an attempt (as there have been, always ill-fated, in the case of goblinkind) to "unite all ogrekind" -- the name doesn't appear to carry much weight in most ogre societies. It should be noted however that ogres have been known to act as mercenaries, or to unite in larger numbers than they could sustain themselves, under the direction of more civilized sentients, capable of supplying food and other resources for them from much further afield than the ogres themselves could reach. Black Steel itself has done this to a certain extent in building up Charracks's defensive force for The Edge, and another case was witnessed by Thaqz in a deep cavern complex near Shalaton, supposedly organized by shadow elves, though the real situation was not wholly clear.
Giants who average much above three meters in height, with the rest of their bodies more or less in proportion, can rarely support themselves in tribal communities of reasonable size. They therefore tend to gather in much smaller family groups, the size and numbers of which presumably depend on the size of the giants and the availability of food and other resources in the region. Those who live in forests and other food-rich localities -- sometimes including lightly-held human borderlands, where they can steal or extort food from human agricultural communities -- typically exist as small, settled nuclear families. On reaching maturity, male giants from such family groups typically set out to find mates among other giant families, and once a match is made, both mates leave their parent groups in search of a place that can support them in the long term while they raise a family of their own. Since woods provide such a rich environment for finding food and material for clothing, shelter, and tools, giants of this type often settle in forests, and are commonly known as woodland giants. It may well be however that giants of sizes normally associated with such small family groups would be able to support much larger communities if they could make use of human agricultural techniques; none who do so however have yet been discovered by Black Steel personnel. On the other hand, giants of this size can sometimes be brought together in large groups by the intervention of another sentient society capable of bringing food and other material together from distant places for the purpose of sustaining the giants together. Black Steel itself has done this, and is managing to support no less than twenty earth giants of great size -- ranging between about three and five meters in height, with bulk at least in proportion -- among its various land holdings.
The largest of the earth giants could hardly support themselves in a significant community even in the lushest of fertile lands. Named rather for their typically tremendous size, "mountain giants" don't necessarily live in mountains, but they may well /look/ like mountains to the terrified and impressionable people who survive to tell their stories. Naturally, these stories are greatly exaggerated however -- whether by tellers in search of glory or by memories colored by fear -- and in spite of the tremendous size often attributed to them, mountain giants rarely exceed five meters in height (though with massive bulk even for that size) in the experience of Black Steel personnel. In areas with little access to food, giants of a size typically associated with woodland giants or even ogres may behave as larger giants do in more fertile realms, further blurring the distinctions between size- or behavior-based classifications.
Often solitary, or moving in very small family groups, mountain giants are likely to be nomadic -- moving out of an area as or before they over-hunt it rather than even trying to live there and conserve its resources -- or range far from settled homes to hunt, for similar reasons. Mountain giants have also been known to rely on human beings to generate sufficient food for their needs in an area of reasonable size. Those who do so by stealing from or murdering the humans who provide their sustenance rarely profit by it, as human ingenuity, in the form of wizards, heroes, or cleverly prepared militia with traps and home-made siege machinery, inevitably slays such monsters or drives them away, but more amicable arrangements are sometimes made with some success, and Black Steel does count several mountain giants among the earth giants with whom it works. For the most part however, mountain giants tend to avoid populated areas, traveling or ranging through relatively untamed wilderness instead, and only stealing from -- preferably distant -- human farmers and the like on rare enough occasion to avoid deadly reactions from major human communities.
One final curiosity relating to magic-based gigantism is an apparently increased probability of conjoined twins. In particular, a form extremely rare among human beings, but noticably common among the smaller giants (relatively speaking, naturally) is that of a body with two heads. In Black Steel's experience, such two-headed giants are best treated as two separate sentient entities who happen to share the same body, and in dealing with them thus, Black Steel has even managed to bring two pairs (which is to say, two bodies and four heads) of them into their military community.