Secret Barrel is a Normal 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, Secret Barrel is Unlimited.
YGOPRODeck lists Secret Barrel for these formats: GOAT, OCG GOAT, Duel Links, Common Charity, Edison, TCG, OCG, Master Duel.
A listed print of Secret Barrel appears in Dark Revelation Volume 1 (DR1-EN101) at Common rarity.
Among markets shown on this page, the lowest listed snapshot for Secret Barrel is about $0.99 on TCGPlayer (prices change frequently).
