Design Aspects as State Changes

Model an Aspect only when its state can change during a Hunt and that change alters capability, behavior, access, or available outcomes. Decorative anatomy and static lore belong elsewhere.

Good physical Aspects include wings, armor, sensory organs, weapons, limbs, or cores. Good nonphysical Aspects include a haunting Anchor, a pact, a territorial rule, a command hierarchy, a memory loop, a social protector, a network connection, or a curse carrier.

Write changesWhen so the GM can adjudicate it without inventing a new subsystem. 'When exposed to the solvent named in the discovered corrosion Truth' is actionable. 'When sufficiently damaged' is vague unless your World defines what sufficient damage means.

The changed effect is the payoff. If breaking a wing still leaves flight fully available, the Aspect was cosmetic. If completing a spirit's memory does not change its behavior or open a Resolution, the state update has no reason to exist.

Keep persistent mutable state on the Hunt, not on the Quarry definition. The Quarry says what 'Wing: Broken' means; the Hunt says this specimen's wing is now Broken. Temporary leverage from an active trap, ward, lure, treatment, or containment setup belongs in active Preparations unless the Quarry explicitly authors it as a lasting Aspect change.