Card Rulings:Imperial Tombs of Necrovalley
- This card can be activated when a Spell/Trap Card is activated, but it cannot be activated when a Spell/Trap effect is activated.
- This card can be activated even if the opponent controls both "Necrovalley" and a "Gravekeeper's" monster.
- While there is no face-up Field Spell Card and the effect of "Gravekeeper's Priestess" is being applied, the field is treated as "Necrovalley". Since "Gravekeeper's Priestess" is also a "Gravekeeper" monster, even if the only card on the field is "Gravekeeper's Priestess", "Hidden Temples of Necrovalley" and "Imperial Tombs of Necrovalley" can be activated.