Emergency Assistance is a Normal 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, Emergency Assistance is Unlimited.
YGOPRODeck lists Emergency Assistance for these formats: Duel Links, Common Charity, Edison, TCG, OCG, Master Duel.
A listed print of Emergency Assistance appears in Ancient Prophecy (ANPR-EN049) at Common rarity.
Among markets shown on this page, the lowest listed snapshot for Emergency Assistance is about $0.11 on Cardmarket (prices change frequently).
