Garma Sword Oath is a Ritual 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, Garma Sword Oath is Unlimited.
YGOPRODeck lists Garma Sword Oath for these formats: OCG GOAT, Duel Links, Common Charity, Edison, TCG, OCG, Master Duel.
A listed print of Garma Sword Oath appears in Tournament Pack 8 (TP8-EN010) at Common rarity.
Among markets shown on this page, the lowest listed snapshot for Garma Sword Oath is about $0.79 on Amazon (prices change frequently).
