Effect: Polymorph is used to alter the fundamental properties of a living creature in a given scene via Complications. To change an unwilling sentient target requires the character to place a 'Polymorphing' Complication on the target; if the Complication's step is lower than the target's Tier they will feel discomfort but be relatively unchanged, when the Complication's step is equal to the target's Tier the target will be partially transformed, and when the Complication's step is higher than the target's Tier they are completely transformed.
At d4 Polymorph can change simple lifeforms into other simple lifeforms, for instance change a spider to a roach.
At d6 Polymorph can change small non-sentient lifeforms into other non-sentient lifeforms; for instance a cat into a fish.
At d8 Polymorph can change large non-sentient lifeforms into other large or small non-sentient lifeforms and vice versa; for instance a cow into puppy or a kitten into a horse. It is also possible to polymorph a non-sentient lifeform to a larger or smaller version of their normal self; for instace change a normal sized scorpion into a bear-sized scorpion.
At d10 Polymorph can change sentient lifeforms into other sentient lifeforms; for instance a human into a goblin. Further when changing non-sentient lifeforms, giant size is on the table.
At d12 Polymorph can change just about any lifeform into just about any other lifeform, up to gargantuan.
Stamina can usually defend against Polymorph. Depending upon the justification for Polymorph, Warding may be able to as well.
Common SFX: The Command SFX can be applied to cause polymorphed non-sentient lifeforms to obey a particular command or task issued when they are transformed.
Common Limits: Polymorph is usually permament, but the Temporary Limit can be taken to represent a form of Polymorph that lasts a certain amount of time and then reverts the target back to their original state unharmed. A similar option is to take the Escape Clause Limit which requires each Transmutation usage to have a fairly reasonable counter (for instance: contact with cold iron, stroke of midnight, exposure to moonlight) that returns the transmuted target to its original form if the condition is met.