Retort is a Counter 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, Retort is Unlimited.
YGOPRODeck lists Retort for these formats: Duel Links, TCG, OCG, Master Duel.
A listed print of Retort appears in Abyss Rising (ABYR-EN080) at Secret Rare rarity.
Among markets shown on this page, the lowest listed snapshot for Retort is about $1.35 on TCGPlayer (prices change frequently).
