Transformation
A transformation is any effect, magical or technological, that alters some essential feature of a creature or object—although the term is more commonly discussed among celemologists than among physicists or engineers. This is a broad definition, and there is occasional semantic dispute as to whether a particular enchantment or other phenomenon qualifies as a transformation or not.
Common transformations
Transformation can take many forms; there are many ways in which things can be changed. Some of the most common and straightforward include transfigurement—changes of shape—, transmutation—change of substance—, and transmagnification, changes of size. These are not mutually exclusive, and many transformations can be considered combinations of several different types of effect.
Transfigurement
Transfigurement describes a change in shape, without necessarily any alteration in substance or size—although in practice many transformations that involve transfigurement do also include such concomitant transformations as well. A transfiguration may mean a change from any shape to any other shape—the complex, organic shape of a living object; the elegant curves of well-designed furniture; simple geometric shapes such as spheres and polyhedra. The specific case when one living creature is transfigured into the shape of another type living creature (such as a human into a large wolf) is called metagenosis (not to be confused with metagenesis), while the yet more specific case of a living creature transfigured into a different form within the same species (including the form of another existing individual) is called repersonation.
Transmutation
Transmutation is the altering of the substance of a creature or object, without necessarily changing its shape. This may include a change in the basic constituents of the object—the elements of its atoms, or the equivalents in the chemistry of another cosmos. Living creatures transmuted may retain all or part their freedom of movement, or may be rendered immobile, either dead or in suspended animation. The latter case is common enough to warrant its own term, agalmatation. Particularly common is agalmatation to stone, known more specifically as petrifaction, though agalmatation to almost any substance is possible.
Transmutation to gaseous, liquid, or particulate substances—fluescence—presents special considerations. The resulting fluid may be made to magically hold its shape, but more commonly the resulting mass of fluid becomes as mutable and irrigid as any other similar mass. While living creatures may (though do not necessarily) still retain their life and consciousness under fluescence, it may be much more difficult to reverse fluescence than other transmutations.
Transmagnification
Transmagnification is the change in an object's size, without in general a change in its shape or chemical composition. Transmagnification is somewhat poorly defined, with some celemologists considering the effect to imply a proportional change in mass, and for a transformation that changes size but retains mass to involve a different transformation altering density, whereas other celemologists consider a change in mass to compose a separate transformation from transmagnification, and to define transmagnification, per se, to conserve mass (and therefore necessarily include a change in density). The former viewpoint is in the majority, however, and is the definition generally followed in the Wongery.
Transformations of living creatures
Living creatures are subject to all the same kinds of transformations that can affect nonliving objects. Of course, on the surface, a straightforward transformation of a living creature into an inanimate form would effectively kill that creature, but it's quite common, especially though not exclusively in arcana that include the existence of souls, for a side effect of the transformation to somehow preserve the transformed creature's life, and often even its awareness—and perhaps even its ability to sense its surroundings, despite its lack of any appropriate organs. (The tactile sense is particularly frequently preserved.) There are also certain kinds of transformations of living creatures not readily applicable to other objects. Some common transformations specifically of living things include transevitation—change in age—and transexion—change in gender.
Mental transformations
Not all transformations involve immediately mensurable physical alterations. Transformations of living creatures may also be purely mental in nature, involving changing subjects' thoughts and emotions, in drastic cases even their personalities. Of course, ultimately even such transformations ultimately have a physical basis, in that they involve alterations in the connections and chemistry of the brain or other mental organs, but they are sufficiently qualitatively different to merit separate consideration. Not all celemologists are happy to classify such effects as transformations at all, preferring to consider them a discrete type of phenomenon, but they remain widely termed mental transformations.
Among the kinds of mental transformation are metamnesis, the modification of memories, and metapathy, the alteration or influence of emotions. One particular kind of metapathy common enough to merit its own term is thelxis, which influences the subject's feelings toward a particular person to make him consider that person a trusted ally worthy of his loyalty and protection—though thelxis often also involves a certain amount of metamnesis to ensure the victim doesn't remember his past dealings with the new object of his affection (who may in fact have been a bitter enemy), or at least includes suppression of his thinking about his prior feelings. Also often enumerated among mental transformations are possession, suspended animation, and mind switch. Animation could also be considered a type of mental transformation, one that gives formerly inanimate objects a mentality.
Other transformations
The above list does not exhaust the possible types of transformation; others exist that don't fall into any of the above categories. Another type of transformation, for instance, is ananome, which transforms multiple objects into multiple different objects, interchanging part of their substance—although ananome is sometimes considered a special case of transfigurement, or vice versa. Transformation can also involve the change of features or forces beyond shape, substance, and size, such as density and color. One drastic kind of transformation is transdimensionality, when an object is somehow projected to a lower or higher number of dimensions.
Partial transformations
A transformation need not necessarily involve an entire object being fully transformed. Most types of transformation may also affect only a part of the subject, whether that subject is living or inanimate. Again, in the case of living subjects, the transformation may include measures to keep the subject alive even when that would otherwise seem improbable—a man half turned to stone may still be alive and conscious, and possibly even able to freely move his stone half (or possibly not). Depending on the arcanum, and perhaps on the particular spell or effect, partial transformations may be very difficult to carry out... or they may be perfectly normal, and it may require extra effort or attention to make sure that an object is transformed in its entirety.
Conversely, some rare transformations may be annective—encompassing not only a single target object, but associated objects as well. In certain unusual arcana, in fact, this may be the norm for transformations of living creatures (or at least for some types of transformation), with magical transformations of people necessarily also affecting their clothing and other accouterments. This is unusual, however; in general, transformations are not annective unless specifically designed that way, and while some arcana may have been so designed, by no means have all. In general, in most arcana, non-annective transformations are the default; transformations described in the Wongery should be assumed to not be annective unless otherwise specified.
Duration
Transformations are more likely than other enchantments to be permanent. This is especially true of transformations with no lingering effects; essentially, such a transformation is not an enchantment at all, but a momentary effect, and there's no enchantment to expire. In fact, reversing the transformation would be equivalent to effecting another transformation with the opposite result. Even when the transformation does have lingering effects, however, those are likely to be in addition to the momentary effect which, again, will not expire. It may be that the transformation includes arrangements for its own cassation after a set period of time and will, therefore, be temporary even if not explicitly revoked, but in most arcana this is not by default the case.
Actually, reversing a transformation may be even more difficult than merely effecting a reverse transformation, because some of the object's prior state may be difficult to restore, especially if further change has happened to the transformed object. Reversing petrifaction, for instance, is often much more difficult than effecting it in the first place, because petrifaction simply involves turning a person or object to stone, whereas reversing petrifaction involves divining what substance each part of the subject was to begin with, and then transmuting each part accordingly. Fluescence may be even more difficult to reverse, since the object's shape may have changed and left its original form as difficult to divine as its substance. Other kinds of transformation may involve similar complications, all of which can combine to make transformations among the most difficult effects and enchantments to reverse.