Weapon Change is a Continuous Spell Card.
Spell Cards are usually activated from the hand on your turn unless their type gives another timing window.
On the current TCG and OCG Forbidden & Limited lists tracked here, Weapon Change is Unlimited.
YGOPRODeck lists Weapon Change for these formats: GOAT, OCG GOAT, Duel Links, Common Charity, Edison, Speed Duel, TCG, OCG, Master Duel.
A listed print of Weapon Change appears in Ancient Sanctuary (AST-041) at Common rarity.
Among markets shown on this page, the lowest listed snapshot for Weapon Change is about $0.04 on Cardmarket (prices change frequently).
