Magicians' Defense is a Continuous Trap Card.
Trap Cards are normally Set first and can be activated on a later turn, often in response to an action.
On the current TCG and OCG Forbidden & Limited lists tracked here, Magicians' Defense is Unlimited.
YGOPRODeck lists Magicians' Defense for these formats: Duel Links, TCG, OCG, Master Duel.
A listed print of Magicians' Defense appears in Yu-Gi-Oh! The Dark Side of Dimensions Movie Pack (MVP1-EN028) at Ultra Rare rarity.
Among markets shown on this page, the lowest listed snapshot for Magicians' Defense is about $0.47 on Cardmarket (prices change frequently).
