“Necrovalley” negates any effect that targets a card or cards in the Graveyard. So “Necrovalley” WILL negate the effect of: “Monster Reborn”, “Premature Burial”, “Call of the Haunted”, “Question”, “Backup Soldier”, “Spear Cretin”, “The Shallow Grave”, “Magician of Faith”, “Fiber Jar”, “Penguin Knight”, and “Agido”.
“Necrovalley” negates costs and effects that require removing cards from the Graveyard. So “Necrovalley” WILL prevent a player from removing cards in the Graveyard from play to activate the effect of “Bazoo the Soul-Eater” or “Chaosrider Gustaph”. “Necrovalley” WILL prevent a player from removing cards in the Graveyard from play to Special Summon “Dark Necrofear” or “Black Luster Soldier – Envoy of the Beginning”. “Necrovalley” WILL negate card effects like “Big Burn”, “Gravedigger Ghoul”, “Disappear”, and “Soul Release”.
“Necrovalley” will NOT negate effects that are activated when a card is sent TO the Graveyard or that activate IN the Graveyard or that count cards in the Graveyard. So it will NOT negate the effects of “Sangan”, “Witch of the Black Forest”, “Black Pendant”, “Giant Rat”, “Mystic Tomato”, “Kuriboh”, “Graceful Charity”, “Sinister Serpent”, “Marie the Fallen One”, “Buster Blader”, “Shadow Ghoul”, “Helpoemer”, “Sword of Deep-Seated”, “Vampire Lord”, “Coffin Seller”, and “Magical Thorn”.
“Necrovalley” will NOT negate effects that do not target a card or cards in the Graveyard. So “Necrovalley” will NOT negate the effects of “Dark Necrofear” (when destroyed and sent to the Graveyard), “Revival Jam”, “Winged Sage Falcos”, “Twin-Headed Behemoth”, “Mystical Knight of Jackal”, and “Red-Moon Baby”.
If “Necrovalley” is on the field, you can Special Summon “Gilasaurus” using its effect, but the effect that lets your opponent Special Summon is negated.
If the effect of “Necrovalley” is negated by “Imperial Order”, then cards that require “Necrovalley” on the field, such as “Gravekeeper’s Assailant”, etc., can still apply their effects because “Necrovalley” is still on the field.
If “Necrovalley” is active, neither player may activate “Book of Life”.
If “Necrovalley” is active and you Special Summon the Spell Card “Gravekeeper’s Servant” with “Magical Hats”, its ATK and DEF will be 500.
Netrep Rulings:
“Necrovalley” will negate and prevent the activation of any effects that target the Graveyard or something within the Graveyard from outside of the Graveyard.
Effects that activate within the Graveyard will not be negated by “Necrovalley.”
Effects of monsters that Special Summon themselves will not be negated by “Necrovalley.”
Effects of cards that return themselves to the hand or the field will not be negated by “Necrovalley.”
“Necrovalley” will prevent the Special Summons of monsters that require removing cards from the Graveyard as a cost to Summon the monster by preventing the summoning player from removing the monsters.
Netrep Q&As:
Q: Can the effects of “Butterfly Dagger – Elma” and “Troop Dragon” still resolve if “Necrovalley” is active on the field?
A: Yes they would still get their effects while “Necrovalley” is in play. Curtis Schultz, 02/02/2004
Q: “Necrovalley” VS. “Skilled Dark Magician” and “Skilled White Magician.” Would the Effects of “Skilled Dark Magician” and “Skilled White Magician” be negated entirely, or just the part about the graveyard?
A: Hand or Deck only in this situation. Curtis Schultz, 12/30/2003