The manipulation of Ichor, the fundamental matter from which all of Elstren was shaped. Among the earliest forms of magic, it is common the world over, seeing applications ranging from sculpting temporary objects, to unmaking existing ones, to crafting magic and even souls from Ichor... as the Architect might.

Form magic, also referred to as Ichor magic, is the control of Ichor, a primordial mass derived from the Well, the Celestial of Being and Chaos. Ichor is everything and nothing, all at once. Given impetus, it could be shaped into virtually anything, but until it is given structure, it exists as a dangerous, thick, dark 'fluid'. It flows like pitch, and grasps at the souls of mortals as it is attracted to any source of substance or structure, potentially causing severe and lethal damage on contact as it removes chunks of soul matter. Those who look at it for long often witness strange images within, most commonly grand visions like planets, stars, and galaxies. Some cultures refer to Ichor as Hollow.

In spite of its danger, Ichor is relatively easy to handle; it is slow moving, weightless, and has no effect on anything other than living people, so it can be safely stored in even the most basic containers so long as they are stable and sealed properly. Likewise, it is abundant; there are vast oceans of Ichor at all sides of Elstren and many underground currents, lakes and rivers of it as well. Form magic, at least all types besides Dissolution, feeds on the creativity of its wielder. Those who can construct complex mental images and have clear ideas of what they desire will have the most success in deriving useful forms from the Ichor, and those with creative verve are more likely to 'motivate' the Ichor to take more stable shape. Anyone, with practice, can coax Ichor into simple shapes, like basic tools or weapons, but the creation of more complex items demands greater mastery and vision.

Usually, items created by mortals with Ichor will dissolve. Inexperienced mages may lose an item's form as soon as they lose focus, but items made by adept mages usually only dissolve once exiting their possession. It is, however, possible to create permanent, 'true' items from Ichor.

Ichor magic is also used in a variety of other ways. Ichor can be used to give souls a mortal form, allowing 'true' resurrection of souls separated from their bodies, or the creation of Thralls, special, Ichor-based beings separated into three types: Chimeras, Lesser, and Greater Thralls. Chimeras are Thralls constructed of many small souls pieced together into a gestalt entity, usually wiped of their individual characteristics and congealed into one, cohesive entity; often made from animals, or from multiple small samples of mortal souls. Lesser Thralls are made with a sacrifice of the wielder's own soul, whereas Greater Thralls are full, living souls trapped in an Ichor-derived body which remains under the control of its creator.

Eventually, those who dedicate their lives to Form magic may find that they become capable of deriving magical energy from it, a particularly rare and impressive feat that allows them to replicate magical abilities from other disciplines. Even higher are Architects, capable of sculpting souls out of Ichor... a power once thought to belong only to the Architect, the Celestial of Logic and Structure.

Form magic has been used since the dawn of Elstren's timeline. It is accessible, comes naturally, and can be valuable in day-to-day life. Many towns make use of Ichor, using wells of Ichor to gain convenient access to it for the creation of disposable tools or weapons. Thralls, particularly of the lesser and chimeric types, are frequently used as guards and laborers.