Dragon Shield is a Equip 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, Dragon Shield is Unlimited.
YGOPRODeck lists Dragon Shield for these formats: Common Charity, TCG, OCG, Master Duel.
A listed print of Dragon Shield appears in Judgment of the Light: Deluxe Edition (JOTL-ENDE3) at Super Rare rarity.
Among markets shown on this page, the lowest listed snapshot for Dragon Shield is about $0.11 on Cardmarket (prices change frequently).
