Ancient Forest is a Field 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, Ancient Forest is Unlimited.
YGOPRODeck lists Ancient Forest for these formats: Duel Links, Edison, TCG, OCG, Master Duel.
A listed print of Ancient Forest appears in Ancient Prophecy (ANPR-EN048) at Super Rare rarity.
Among markets shown on this page, the lowest listed snapshot for Ancient Forest is about $0.20 on Amazon (prices change frequently).
