A person's a thing that represents an entity outside the game that is capable of action in the game.

An animal's a thing that may move without another thing's behaviour triggering it.

A plant's a nonperson that may move with a person's behaviour triggering it, and without its movement being described by a person.

A mineral's a nonperson that may move if its movement is described by a person.

A fixture's a nonperson that can move only if triggered by a nonperson's behaviour.

An abstraction's a nonperson that cannot move.

A fruitholder's a thing of a type that may possess Oranges.