Child's Play is a Continuous 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, Child's Play is Unlimited.
YGOPRODeck lists Child's Play for these formats: Duel Links, Common Charity, TCG, OCG, Master Duel.
A listed print of Child's Play appears in Savage Strike (SAST-EN069) at Common rarity.
Among markets shown on this page, the lowest listed snapshot for Child's Play is about $0.18 on Cardmarket (prices change frequently).
