Backup Soldier 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, Backup Soldier is Unlimited.
YGOPRODeck lists Backup Soldier for these formats: GOAT, OCG GOAT, Duel Links, Common Charity, Edison, TCG, OCG, Master Duel.
A listed print of Backup Soldier appears in Dark Beginning 1 (DB1-EN082) at Common rarity.
Among markets shown on this page, the lowest listed snapshot for Backup Soldier is about $0.05 on Cardmarket (prices change frequently).
