Hero Signal 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, Hero Signal is Unlimited.
YGOPRODeck lists Hero Signal for these formats: GOAT, OCG GOAT, Duel Links, Speed Duel, Common Charity, Edison, TCG, OCG, Master Duel.
Hero Signal belongs to the Elemental HERO archetype—use that tag when searching for engine pieces and tech options.
A listed print of Hero Signal appears in Dark Revelation Volume 3 (DR3-EN229) at Rare rarity.
Among markets shown on this page, the lowest listed snapshot for Hero Signal is about $0.07 on Cardmarket (prices change frequently).
