Dark Room of Nightmare 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, Dark Room of Nightmare is Unlimited.
YGOPRODeck lists Dark Room of Nightmare for these formats: GOAT, OCG GOAT, Duel Links, Common Charity, Edison, TCG, OCG, Master Duel.
A listed print of Dark Room of Nightmare appears in Dark Revelation Volume 1 (DR1-EN030) at Common rarity.
Among markets shown on this page, the lowest listed snapshot for Dark Room of Nightmare is about $0.10 on Cardmarket (prices change frequently).
