Card Rulings:Book of Moon

Mentions in Other Rulings

 * Ancient Forest: If a monster attacks and is flipped face-down by "Book of Moon", it will still be destroyed.


 * Flying Fortress SKY FIRE: If your opponent flips a card face-down, such as with “Book of Moon”, you can activate effect #2 of “Flying Fortress SKY FIRE” to destroy the Set card.


 * Future Visions: If "Book of Moon" is Chained to the effect of "Future Visions" the monster will still be removed from play.


 * Koa'ki Meiru Tornado: If your opponent Chains "Book of Moon" to this effect to turn a Special Summoned monster face-down, it will still be destroyed.


 * Mysterious Triangle: If an effect is chained to “Mysterious Triangle” that removes the target’s A-Counter, it is not destroyed. (Example: if it is flipped face-down with “Book of Moon”.)


 * Rekindling: If a monster Special Summoned by "Rekindling" is flipped face-down by "Book of Moon" it is not removed from play during End Phase.


 * Shiny Black "C": If "Book of Moon" is Chained to the effect of "Shiny Black C" [sic] to flip the targeted monster face-down, the monster is not destroyed because it cannot be identified as a Synchro Monster.


 * Solitaire Magician: If you activate this effect and the targeted "Fortune Lady" monster is flipped face-down by "Book of Moon," the effect of "Solitaire Magician" will not apply. If the monster targeted to be destroyed is flipped face-down by "Book of Moon," the effect of "Solitaire Magician" resolves normally.


 * Spiders' Lair: If a monster being kept in Defense Position by "Spiders' Lair" is flipped face-down with "Book of Moon," the effect of "Spiders' Lair" is no longer applied to it.


 * Star Blast: If a monster affected by “Star Blast” is face-up on the field, and is then flipped face-down (with “Book of Moon”, etc.) then the effect of “Star Blast” is wiped and the monster’s Level returns to normal.


 * Widespread Dud: If "Book of Moon" is Chained to "Widespread Dud" and flips one of the targeted monsters face-down, only the other one will continue to be targeted.

OCG Rulings

 * You cannot activate this card during the Damage Step.

In Chain to an Effect which Targets

 * Dimensional Prison: If "Book of Moon" is used on an attacking monster, then that monster is no longer considered to be an attacking monster. Thus, if "Book of Moon" is Chained to an effect like "Dimensional Prison" or "Sakuretsu Armor" and changes the monster to face-down Defense Position, then the effect of "Sakuretsu Armor" does not resolves, so the attacking monster is not destroyed (or removed from play, and so on).


 * Earthbound Immortal Uru: If an effect like "Book of Moon" is Chained to the effect of "Earthbound Immortal Uru" so that the targeted monster is not face-up on the field when the effect of "Earthbound Immortal Uru" resolves, then you cannot gain control of the monster.


 * Effect Veiler: When resolving the effect of "Effect Veiler", if the targeted monster is face-down, then do not apply the effect of "Effect Veiler" and do not negate the targeted monster's effect.
 * Example: "Trishula, Dragon of the Ice Barrier" activates its effect, and "Effect Veiler" is Chained and targets "Trishula, Dragon of the Ice Barrier", and then "Book of Moon" is Chained also targeting "Trishula, Dragon of the Ice Barrier". Resolving backwards, "Trishula, Dragon of the Ice Barrier" is flipped face-down, so that "Effect Veiler" cannot negate its effect.


 * Give and Take: If "Book of Moon" etc is chained to "Give and Take" so that the monster targeted by "Give and Take" is no longer face-up on the field when "Give and Take" resolves, then you still Special Summon a monster to your opponent's field.


 * Level Eater: If the effect of "Level Eater" cannot lower the monster's Level by one - such as if an effect like "Book of Moon" or "Compulsory Evacuation Device" is chained to so that the targeted Level 5 or higher monster is not face-up on the field at resolution - then "Level Eater" is not Special Summoned.


 * Machine Duplication: If the targeted monster is no longer face-up on the field when resolving "Machine Duplication" - such as if "Book of Moon" or "Compulsory Evacuation Device" is chained - then you cannot Special Summon any monsters of the same name from your Deck.


 * Sakuretsu Armor: See above; listed under "Dimensional Prison".


 * Scrap-Iron Scarecrow: If the monster is flipped face-down by "Book of Moon" before "Scrap-Iron Scarecrow" can negate the attack, then "Scrap-Iron Scarecrow" is still set.


 * Shiny Black "C": If an effect like "Book of Moon" is chained to the effect of "Shiny Black "C"" so that the Synchro Monster is face-down when resolving the effect of "Shiny Black "C"", then "Shiny Black "C"" will not destroy the face-down monster.


 * Shock Troops of the Ice Barrier: If an effect like "Book of Moon" or "Ring of Destruction" is activated in Chain to the effect of "Shock Troops of the Ice Barrier" so that the WATER monster is no longer face-up on the field at resolution, then the effect of "Shock Troops of the Ice Barrier" cannot destroy the WATER monster, so you cannot add an "Ice Barrier" monster from your Deck to your hand.


 * Test Tiger: If the "Gladiator Beast" monster targeted by "Test Tiger" is not face-up on the field at resolution (for example, "Book of Moon" or "Ring of Destruction" was chained to the effect), then "Test Tiger" resolves without effect.


 * Tragoedia: If "Book of Moon" is chained to "Tragoedia"'s effect and targets the same monster, then the monster is face-down when "Tragoedia"'s effect resolves, so control of the monster does not change.


 * Transforming Sphere: If an effect like "Book of Moon" is Chained to the effect of "Transforming Sphere" so that the monster is face-down when resolving the effect of "Transforming Sphere", then that face-down monster is still equipped to "Transforming Sphere". The monster is equipped face-down to "Transforming Sphere", so the ATK of "Transforming Sphere" does not increase.  During the End Phase, the face-down monster is Special Summoned to your opponent's side of the field in face-up Defense Position.


 * Tuner's Scheme: If "Book of Moon" is Chained to the activation of "Tuner's Scheme" so that the targeted Synchro Monster is face-down when "Tuner's Scheme" resolves, then control of the face-down Synchro Monster does not change.


 * Underground Arachnid: "Underground Arachnid" can only equip an opponent's face-up monster to itself.  If an effect like "Book of Moon" is Chained to the effect of "Underground Arachnid" so that the monster is face-down when resolving the effect of "Underground Arachnid", then the monster is not equipped and it remains on the opponent's side of the field.


 * Widespread Dud: If "Widespread Dud" is activated and an effect like "Book of Moon" or "Compulsory Evacuation Device" is Chained so that one of the targeted monsters is not face-up on the field when "Widespread Dud" resolves, then only the monster which is still on the field will remain targeted by "Widespread Dud". If that monster is removed from the field, then "Widespread Dud" is destroyed.

On Monsters Remembering/Forgetting How they were Summoned

 * Genex Neutron: If "Genex Neutron" is flipped face-down, such as with "Book of Moon", and then flipped face-up during the turn in which it was Normal Summoned, then you can still activate "Genex Neutron"'s effect during the End Phase.


 * Koa'ki Meiru Tornado: The effect of "Koa'ki Meiru Tornado" can destroy face-down monsters, such as monsters Special Summoned face-down by "The Shallow Grave" or monsters that were Special Summoned and then flipped face-down by "Book of Moon".


 * Majestic Mech - Goryu: If "Majestic Mech - Senku" is flipped face-down with "Book of Moon" and then flipped face-up during the same turn, then its effect which sends it to the Graveyard will still activate during the End Phase. If "Majestic Mech - Ohka" is Normal Summoned without Tributes, or if "Majestic Mech - Goryu" is Normal Summoned with one Tribute, and either is flipped face-down with "Book of Moon" and then flipped face-up during the same turn, then its effect which sends it to the Graveyard will no longer activate during the End Phase.  If any of these monsters is face-down during the End Phase, then the monster will not be sent to the Graveyard.


 * Majestic Mech - Ohka: See above; listed under "Majestic Mech - Goryu".


 * Majestic Mech - Senku: See above; listed under "Majestic Mech - Goryu".


 * Mosaic Manticore: If "Mosaic Manticore" is flipped face-down by "Book of Moon" and then flipped face-up before the next Standby Phase after it was Tribute Summoned, then its effect will activate as long as it is still face-up during the Standby Phase.


 * Synchro Strike: If a Synchro Monster is flipped face-down with "Book of Moon" and then flipped face-up, it cannot be targeted by "Synchro Strike".

On Monsters which Must Remain Face-Up

 * Card Rulings:: If an effect like "Book of Moon" or "Compulsory Evacuation Device" is Chained to the effect of ":" so that you control no Level 1 Fairy-Type monsters at resolution, then you cannot Special Summon a Fairy-Type monster from your hand.


 * Lightsworns: If an effect like "Book of Moon" or "Compulsory Evacuation Device" is chained to the effect of "Jain, Lightsworn Paladin" or "Judgment Dragon" which sends cards from the Deck to the Graveyard during the End Phase so that "Jain, Lightsworn Paladin" is not face-up on the field when its effect is resolving, then you do not apply the effect and you do not send cards from the Deck to the Graveyard.


 * Naturia Barkion: If an effect like "Book of Moon" or "Offerings to the Doomed" is chained to the effect of "Naturia Barkion" so that "Naturia Barkion" is not face-up on the field during the resolution of its effect, then the effect of "Naturia Barkion" resolves without effect and the activation of the Trap Card is not negated.


 * Naturia Beast: If "Book of Moon" or "Ring of Destruction" is chained to the effect of "Naturia Beast" so that "Naturia Beast" is not face-up on the field when its effect resolves, then the Spell Card is not negated.


 * Card Rulings:: If ":" is not face-up on the field when its effect resolves - for example, "Book of Moon" or "Compulsory Evacuation Device" was Chained to the effect - then the activation of the Spell/Trap Card is not negated.


 * Card Rulings:: If an effect like "Book of Moon" or "Ring of Destruction" is Chained to the effect of ":" so that ":" is not face-up on the field at resolution, then the effect of ":" cannot negate the activation of an Effect Monster's effect.


 * Shiba-Warrior Taro: If an effect like "Book of Moon" is Chained to the effect of "Shiba-Warrior Taro" so that "Shiba-Warrior Taro" is face-down at resolution, then the effect of "Shiba-Warrior Taro" is not applied and "Shiba-Warrior Taro" is not returned to the hand.

On Removing Lingering Effects

 * Ally of Justice Nullfier: If "Ally of Justice Nullfier" negates a monster's effect and then the monster is flipped face-down by "Book of Moon", then the monster's effect is no longer negated.


 * Assault Revival: When an "/Assault Mode" monster is Special Summoned by "Assault Revival", if it is flipped face-down by "Book of Moon" etc, the effect of "Assault Revival" is no longer applied. The monster does not have its effects negated, can be Tributed, and is not removed from play when it leaves the field.


 * Battle Fader: If "Battle Fader" is Special Summoned by its effect and then flipped face-down by an effect like "Book of Moon", then the effect "If this card is removed from the field, then it is removed from play." of ":" is no longer applied.


 * Beast King Barbaros: If "Beast King Barbaros" or "Fusilier Dragon, the Dual-Mode Beast" is Normal Summoned without Tributes and has its ATK/DEF changed, then if it is flipped face-down by an effect like "Book of Moon", then the effect which changes its ATK/DEF is no longer applied, so "Fusilier Dragon, the Dual-Mode Beast" returns to 2800/2000. Also, if it is removed from play by "Interdimensional Matter Transporter", then the effect which changes its ATK/DEF is no longer applied as soon "Fusilier Dragon, the Dual-Mode Beast" is removed from the field, so "Fusilier Dragon, the Dual-Mode Beast" returns to 2800/2000.


 * Blackwing - Shura the Blue Flame: When "Blackwing - Shura the Blue Flame" Special Summons a monster, if the Special Summoned monster is flipped face-down by "Book of Moon"/etc, then the Special Summoned monster's effect is no longer negated.


 * Blackwing - Vayu the Emblem of Honor: If the monster Special Summoned by "Blackwing - Vayu the Emblem of Honor" is flipped face-down by an effect like "Book of Moon", then you no longer apply the effect "the effect(s) of the Special Summoned monster by this effect is negated" of "Blackwing - Vayu the Emblem of Honor". Once the Synchro Monster if flipped face-up, its effect will no longer be negated.


 * Cyber Eltanin: If "Cyber Eltanin" is flipped face-down by an effect like "Book of Moon", then its effect of increasing its ATK is no longer applied. If "Cyber Eltanin" is later flipped face-up, then its ATK will be 0.


 * Dark End Dragon: If "Light End Dragon"/"Dark End Dragon" activates its effect, and is then flipped face-down by "Book of Moon", then the ATK/DEF decrease will disappear when "Light End Dragon"/"Dark End Dragon" is flipped face-up again.


 * Djinns of Rituals: If a Ritual Monster is flipped face-down by an effect like "Book of Moon" after it was Ritual Summoned by using monsters like "Djinn Releaser of Rituals" or "Djinn Presider of Rituals", then the effect of "Djinn Releaser of Rituals" is no longer applied. Afterwards, even if the Ritual Monster is flipped face-up again, then the effect of "Djinn Releaser of Rituals" is still no longer applied.


 * Doomkaiser Dragon/Assault Mode: If "Book of Moon" etc flips face-down a Zombie-Type monster Special Summoned by "Doomkaiser Dragon/Assault Mode", then the effect of "Doomkaiser Dragon/Assault Mode" is no longer applied. The monster does not have its effects negated and is not destroyed during the End Phase, even if it is later flipped face-up.


 * Eccentric Boy: If a Synchro Monster" which used "Eccentric Boy" as a Synchro Material Monster is flipped face-down by an effect like "Book of Moon", then from that point onward the effect of "Eccentric Boy" is no longer applied. Afterwards, the monster can activate its effects once it is flipped, and the effects which were negated are now applied.  Also afterwards, the monster is not removed from play when it is removed from the field.


 * Elemental HERO Neos Knight: If "Elemental HERO Neos Knight" is flipped face-down by an effect like "Book of Moon", then its ATK-increasing effect is no longer applied, even if "Elemental HERO Neos Knight" later becomes face-up. Thus, the ATK of "Elemental HERO Neos Knight" will no longer be increased once it becomes face-up.


 * Fire Ant Ascator: If a monster which was Special Summoned by the effect of "Fire Ant Ascator" is flipped face-down by an effect like "Book of Moon", then the effect "Its effect(s) is negated, and it is sent to the Graveyard during the End Phase of this turn." of "Fire Ant Ascator" is no longer applied, and the Special Summoned monster's effects are now applied.


 * Flelf: After the effect of "Flelf" resolves and increases its Level, if "Flelf" is flipped face-down by "Book of Moon" or banished by "Interdimensional Matter Transporter", then you no longer apply the Level-increasing effect.


 * Fusilier Dragon, the Dual-Mode Beast: See above; listed under "Beast King Barbaros".


 * Hundred Eyes Dragon: If "Book of Moon" flips "Hundred Eyes Dragon" face-down, then you no longer apply the effect of "Hundred Eyes Dragon" which has it gain a card's effects. If "Hundred Eyes Dragon" is flipped face-up during the same turn, then you can activate its effect a second time to gain the effects of a second Level 6 or lower DARK monster.


 * Infernity General: If a monster Special Summoned by "Infernity General" is flipped face-down with "Book of Moon", then when it becomes face-up again you can activate and apply its effects.


 * Light End Dragon: See above; listed under "Dark End Dragon".


 * Montage Dragon: If "Montage Dragon" is flipped face-down by "Book of Moon" its ATK becomes 0.


 * Morphtronic Scopen: For the "Attack Position:" effect of "Morphtronic Scopen", destroying the monster during the End Phase does not start a Chain. If the Special Summoned monster is flipped face-down with "Book of Moon" or removed from play temporarily with "Interdimensional Matter Transporter", then the monster is not destroyed during the End Phase.


 * Numbing Grub in the Ice Barrier: If "Numbing Grub in the Ice Barrier" is flipped face-down with "Book of Moon", its effect disappears, and is not re-applied if "Numbing Grub in the Ice Barrier" is flipped face-up again.


 * Overdoom Line: The increase to ATK from "Overdoom Line" lasts as long as the monster remains face-up on the field. If the monster is flipped face-down by "Book of Moon" or is removed from the field by "Interdimensional Matter Transporter", then the increase to ATK is not reapplied.


 * Rekindling: If a monster is Special Summoned by "Rekindling" and then flipped face-down by an effect like "Book of Moon", then the effect of "Rekindling" is no longer applied, so the monster will not be removed from play during the End Phase.


 * Synchro Change: If the Synchro Monster Special Summoned by "Synchro Change" is flipped face-down by an effect like "Book of Moon", then the effect of "Synchro Change" is no longer applied as soon as the monster is flipped face-down. Thus, the monster's effects will be applied once it is flipped face-up.


 * The Fabled Ganashia: If "The Fabled Ganashia" is Special Summoned by its effect, then when it is flipped face-down by an effect like "Book of Moon" its effect "when this card is removed from the field, it is removed from play" is no longer applied. Afterwards, "The Fabled Ganashia" is not removed from play if it is removed from the field.


 * Totem Dragon: If "Totem Dragon" is flipped face-down by an effect like "Book of Moon" after it is Special Summoned by its own effect, then the effect "remove it from play when it is removed from the field." is no longer applied as soon as "Totem Dragon" is flipped face-down. Afterwards, "Totem Dragon" will not be removed from play if it is removed from the field.


 * Worm Yagan: After "Worm Yagan" Special Summons itself from the Graveyard, if it is flipped face-up and then face-down by an effect like "Book of Moon", then as soon as it becomes face-down the effect "When this card is removed from the field, it is removed from play." no longer is applied, so it will no longer be removed from play if it is removed from the field.


 * Worm Zero: If "Worm Zero" is flipped face-down by an effect like "Book of Moon", then its ATK becomes 0 and the effects which it acquired disappear. If "Worm Zero" is then flipped face-up, then its ATK will remain at 0, and its effects are not re-applied.

On Setting Monsters whose Control Changed

 * Brain Control: If you gain control of an opponent's monster with a card like "Brain Control" or "Enemy Controller" and then the monster is flipped face-down by an effect like "Book of Moon", then the effect of "Enemy Controller" is still applied, and control of the monster still returns back to your opponent during the End Phase.


 * Card Rulings:: If you gain control of a monster by the effect of ":" and afterwards the monster is flipped face-down by an effect like "Book of Moon", then the monster is no longer targeted by ":". The monster will remain on your side of the field, even if ":" is removed from the field or if the monster is later flipped face-up.  Also, if the monster is removed from the field, then it is not removed from play and ":" is not destroyed.


 * Enemy Controller: See above; listed under "Brain Control".


 * Reptilianne Viper: If you gain control of a monster via the effect of "Reptilianne Viper", then you retain control of the monster, even if its ATK is no longer 0 or if the monster is flipped face-down by an effect like "Book of Moon".

On Setting Referenced Monsters

 * Card Rulings:: When resolving the effect of ":", if the ":" which activated the effect is face-down - for example, "Book of Moon" was Chained to the effect and flipped :" face-down - then the targeted monster is not destroyed.


 * Blackwing - Silverwind the Ascendant: If an effect like "Compulsory Evacuation Device" or "Book of Moon" is Chained to the effect of "Blackwing - Silverwind the Ascendant" so that "Blackwing - Silverwind the Ascendant" is not face-up on the field when resolving its effect, then the targeted monsters are not destroyed. If the effect of "Blackwing - Silverwind the Ascendant" targets two monsters and an effect like "Compulsory Evacuation Device" or "Book of Moon" is Chained so that only one of the targeted monsters is face-up on the field when resolving the effect, then the remaining monster is still destroyed.


 * De-Synchro: Suppose that a Synchro Monster is flipped face-down by "Book of Moon" and then flipped face-up again. If it is targeted by "De-Synchro", then it returns to the Extra Deck, and you can Special Summon the Synchro Material Monsters from your Graveyard.


 * Fabled Gallabas: If an effect like "Book of Moon" or "Raigeki Break" is Chained to the effect of "Fabled Gallabas" so that "Fabled Gallabas" is not face-up on the field at resolution, then the effect of "Fabled Gallabas" resolves without effect and the monster is not destroyed.


 * Inferno Reckless Summon: If cards like "Book of Moon" or "Raigeki Break" is Chained to "Inferno Reckless Summon" so that neither player has any face-up monsters at resolution, then neither player Special Summons monsters with the same name. If only your opponent has monsters, then your opponent still Special Summons monsters with the same name, even though you do not have any face-up monsters.  If only you have monsters, then only you Special Summon monsters with the same name.


 * Moon Dragon Quilla: If an effect like "Book of Moon" or "Compulsory Evacuation Device" is Chained to the Life Point-increasing effect of "Moon Dragon Quilla " so that the attacking monster is not face-up on the field when the effect of "Moon Dragon Quilla " resolves, then you do not increase your Life Points.

Versus Activation Conditions

 * Core Blast: When resolving "Core Blast", if you do not control any "Koa'ki Meiru" monsters - for example, if "Book of Moon" or "Compulsory Evacuation Device" is Chained - then the effect of "Core Blast" which destroys the opponent's cards still resolves.


 * Fortune Lady Water: If an effect like "Book of Moon" or "Compulsory Evacuation Device" is Chained to the effect of "Fortune Lady Water" so that there are no other face-up "Fortune Lady" monsters on your side of the field when resolving the effect of "Fortune Lady Water", then you can still draw cards from your Deck.


 * Card Rulings:/Card Rulings:: If a monster like ":" or ":" is selected as an attack target and the attacking monster is then no longer face-up on the field - for example, "Sakuretsu Armor" or "Book of Moon" was activated - then ":" is still destroyed at the end of the Battle Phase.


 * Worm Bait: If an effect like "Book of Moon" or "Interdimensional Matter Transporter" is Chained to the effect of "Worm Bait" so that you do not have "Worm Bait" [sic] face-up on your side of the field when resolving the effect of "Worm Bait", then the "Worm Tokens" are still Special Summoned.

Miscellaneous

 * Dark End Dragon: If "Light End Dragon"/"Dark End Dragon" activates its effect, and is then flipped face-down by "Book of Moon", then the ATK/DEF decrease will disappear when "Light End Dragon"/"Dark End Dragon" is flipped face-up again.


 * Fabled Raven: If an effect like "Book of Moon" or "Compulsory Evacuation Device" is chained to the effect of "Fabled Raven" so that "Fabled Raven" is not face-up on the field when resolving its effect, then you still resolve the effect which makes you discard from your hand, even though you cannot resolve the effect which raises the ATK of "Fabled Raven".


 * Future Visions: If "Book of Moon" is chained to the effect of "Future Visions" so that the monster is no longer face-up when "Future Visions" resolves, then the face-down monster is still removed from play. However, the monster will be removed from play face-up, because the monster removed from play by "Future Visions" is always removed from play face-up.


 * Gandora the Dragon of Destruction: If "Book of Moon" is Chained to the effect of "Gandora the Dragon of Destruction" to flip "Gandora the Dragon of Destruction" face-down, then "Gandora the Dragon of Destruction" is not destroyed by its effect and remains on the field.


 * Light End Dragon: See above; listed under "Dark End Dragon".


 * Number 16: Shock Master: If a card like "Book of Moon" or "Compulsory Evacuation Device" is Chained to the effect of "Number 16: Shock Master" so that it is not on the field when its effect resolves, then you still apply its effect. If, instead, you apply the effect of "Number 16: Shock Master" and afterwards it is removed from the field or flipped face-down, then you keep applying its effect.


 * Summoner of Illusion: If an effect like "Book of Moon" is Chained to the Flip Effect of "Summoner of Illusions" so that "Summoner of Illusions" is face-down when its effect is resolving, then you still cannot Tribute "Summoner of Illusions" when resolving its effect.


 * Token Monsters: Token Monsters, like the "Sheep Token", cannot be flipped face-down. Thus, you cannot activate "Book of Moon" by targeting a "Sheep Token".

Mentions in Other Rulings

 * During the Damage Step, in general, you cannot activate Spell/Trap Cards other than Counter Trap Cards and ATK/DEF-increasing/decreasing effects. Thus, you cannot activate "Book of Moon" nor "Raigeki Break", but you can activate the Counter Trap "Divine Wrath" during the Damage Step.


 * Dark Simorgh: While "Dark Simorgh" is on the field, the opponent cannot Set cards on the field, so he cannot activate the effect of "Book of Moon", and neither player may activate "The Shallow Grave".


 * Priority: When the Turn Player Sets a Spell/Trap/Monster Card by the effect of "Book of Moon"/"The Shallow Grave"/etc or from the hand, he may not use Priority to activate the Ignition Effect of a monster. If the Turn Player does not use Priority to activate an Ignition or a Spell Speed 2+ Effect in response to the Set, then the opponent can activate a Spell Speed 2+ Effect in response to the Set.  Also, the Turn Player cannot Set multiple cards simultaneously - he must Set one, then pass Priority, and then Set the second, etc.


 * Karakuri Anatomy: If you flip a "Karakuri" monster face-down with "Book of Moon", then a Karakuri Counter will not be placed.


 * Spirit Reaper: If "Spirit Reaper" is targeted by an effect, then the effect of "Spirit Reaper" destroys it after the effect finishes resolving and only if "Spirit Reaper" is face-up on the field. Thus, if "Spirit Reaper" is targeted by "Book of Moon", then "Spirit Reaper" is face-down after the effect finishes resolving, so "Spirit Reaper" is not destroyed.

Previously Official Rulings
{{Previously Official Rulings |UDE's Rulings =
 * When you activate "Book of Moon" during the Battle Step to flip your defending monster into face-down Defense Position, the attack resolves as normal. No replay occurs because the possible attack targets on your side of the field did not change.


 * When you activate "Book of Moon" during the "Battle Step" to flip an attacking monster into face-down Defense Position, the attack stops. No replay is triggered. The attacking monster cannot change its battle position in "Main Phase 2", because it is still considered to have declared an attack. (So it cannot be Flip Summoned in "Main Phase 2".)


 * If you are attacking, and you chain "Book of Moon" to your opponent’s "Mirror Force" to flip one of your monsters face-down, that monster is not destroyed by "Mirror Force".


 * If you chain "Book of Moon" to "Magic Cylinder", "Ring of Destruction", or "Trap Hole" to flip the target of any of those cards face-down, the card’s effect disappears. (See "Activation & Targeting Eligibility" in the Advanced FAQ.)


 * If you chain "Book of Moon" to "Bottomless Trap Hole", the now face-down monster will not be destroyed by "Bottomless Trap Hole", but any other appropriate monsters Summoned at the same time will still be destroyed.


 * If you use "Book of Moon" on "Dream Clown", "Dream Clown"’s effect is not activated.


 * If you chain "Book of Moon" to the activation of a Flip Effect Monster’s effect, such as "Fiber Jar", "Book of Moon" flips the monster face-down again, but the Flip Effect still resolves as normal.


 * You cannot flip a Monster Token face-down because Monster Token are always face-up.


 * You cannot activate "Book of Moon" while "Light of Intervention" is active.

Mentions in Other Rulings

 * 3-Hump Lacooda: If your opponent chains ... "Book of Moon" to the activation of "3-Hump Lacooda"'s effect, the effect is not negated.


 * Adhesion Trap Hole: If a monster affected by "Adhesion Trap Hole" is flipped face-down (with "Book of Moon", etc.), "Adhesion Trap Hole"'s effect disappears and the monster's ATK is back to normal.


 * Allure Queen LV3: If "Book of Moon" is chained to the activation of "Allure Queen LV3's" effect to turn the "Allure Queen" face-down, then the monster that was targeted is destroyed. It cannot be equipped to a face-down monster.


 * Ancient Gear Castle: For “Ancient Gear Castle”, “Set” means to Set from the hand. It does not include using “Book of Moon” ... to flip a monster face-down...


 * Armor Exe: If you Summon "Armor Exe", flip it face-down with "Book of Moon", and flip it face-up with "Book of Taiyou", it CAN attack because its non-attack effect was reset and because flipping it face-up with "Book of Taiyou" was NOT a Flip Summon.


 * Big Shield Gardna: If "Big Shield Gardna" is targeted with a Spell Card, you may chain "Book of Moon" to flip it face-down, then it can negate the Spell Card and will flip back to face-up Defense Position.


 * Bottomless Trap Hole: If the opponent Summons a monster, then you activate "Bottomless Trap Hole", and the opponent chains "Book of Moon" to flip the Summoned monster face-down, it is not removed from play by the effect of "Bottomless Trap Hole".


 * Burst Stream of Destruction / Dark Magic Attack: If you activate "Burst Stream of Destruction", and the "Blue-Eyes White Dragon" is...flipped face-down with "Book of Moon"..."Burst Stream of Destruction"'s effect still resolves.


 * Chain Disappearance: If your opponent activates "Chain Disappearance" and...you chain "Book of Moon", the monster will be face-down, so no cards are removed from play for the effect of "Chain Disappearance".


 * Chaos Sorcerer: If you select a face-up monster with "Chaos Sorcerer"'s effect, and your opponent chains "Book of Moon" to flip the monster face-down, then "Chaos Sorcerer"'s effect disappears. But even if "Chaos Sorcerer"'s effect disappears, its effect was activated so it cannot attack or activate its effect again.


 * Charmers: If “Book of Moon” is chained to the Flip Effect of a “Charmer” to flip the target monster face-down, the effect of the “Charmer” disappears.


 * Curse of Anubis: If "Book of Moon" is chained to "Curse of Anubis" to flip a monster face-down, the effect of "Curse of Anubis" is not applied to the monster that was flipped face-down.


 * Cyber Laser Dragon: If "Book of Moon" is chained to "Cyber Laser Dragon's" effect to turn either the targeted monster or "Cyber Laser Dragon" face-down, its effect will not resolve because both monsters' ATK / DEF values can no longer be compared.


 * D.D.M. - Different Dimension Master: If the opponent chains "Book of Moon" to his effect and flips "D.D.M. - Different Dimension Master" face-down, you still resolve his effect.


 * Dark Magic Attack: If you activate "Dark Magic Attack", and the "Dark Magician" is removed from the field with "Interdimensional Matter Transporter" or "Compulsory Evacuation Device", or flipped face-down with "Book of Moon", or destroyed by "Ring of Destruction", "Dark Magic Attack"'s effect still resolves.


 * Dark Paladin: If you activate "Dark Paladin"'s Spell-negating effect, and your opponent chains "Book of Moon" to flip "Dark Paladin" face-down, the Spell Card is still negated even though "Dark Paladin" is face-down.


 * Desert Sunlight: If you have a face-up Flip Effect monster, you can activate "Desert Sunlight", and chain "Book of Moon", another "Desert Sunlight", and another "Book of Moon". When the chain resolves, you will flip the monster down, then up, then down, then back up. The Flip Effect activates twice, and they wait to create a new chain after the current one resolves. For example, if the Flip Effect monster is "Morphing Jar", its effect will activate twice in a chain, as Chain Link 1 and Chain Link 2, they resolve in reverse order, and both players will discard and draw 5 cards, then discard and draw 5 cards again.


 * Doomcaliber Knight: Even if "Book of Moon", etc., is chained to "Doomcaliber Knight's" effect and flips the Effect Monster face-down, the Effect Monster's effect is still negated by "Doomcaliber Knight" and it is still destroyed.


 * Double Snare: You can only destroy face-up cards with the effect of "Double Snare". The opponent may chain "Book of Moon" to your "Double Snare" to flip his / her monster face-down, and it will not be destroyed.


 * Enemy Controller: If you activate either of "Enemy Controller"'s effects, and your opponent chains "Book of Moon" to flip the target monster face-down, its targeting conditions are no longer correct when "Enemy Controller" resolves and "Enemy Controller"'s effect disappears.


 * Enemy Controller: If you take control of your opponent's monster with "Enemy Controller", and then the monster is flipped face-down with "Book of Moon", control of the monster is still returned to the opponent (the original controller) during the End Phase.


 * Giant Kozaky: If "Giant Kozaky" is destroyed while face-down, then its effect that inflicts damage is not activated. If "Giant Kozaky" is face-up on the field and is targeted by "Tribute to the Doomed", and you chain "Book of Moon" so that "Giant Kozaky" is face-down when destroyed by "Tribute to the Doomed", there is no damage.


 * Gorgon's Eye: If "Gorgon's Eye" is active and you activate a monster effect, and "Book of Moon" is chained to flip the monster into Defense Position, the monster's effect is still applied and is not negated by "Gorgon's Eye" because it was activated properly.


 * Grave Ohja: If "Grave Ohja" is attacked, and you activate "Book of Moon" to flip another monster on your side of the field face-down, "Grave Ohja" has already been selected as the attack target so the attack proceeds as normal.


 * Huge Revolution: When your opponent chains "Book of Moon" to your "Huge Revolution" and flips 1 of the 3 monsters face-down, "Huge Revolution" has already been activated correctly, so its effect still resolves.


 * Legacy Hunter: ...if "Legacy Hunter" attacks a face-up monster and "Book of Moon" flips it face-down, "Legacy Hunter's" effect DOES apply.


 * Levia-Dragon - Daedalus: If an effect is chained to “Levia-Dragon - Daedalus'” effect to flip “Levia-Dragon - Daedalus" face-down, it is still not destroyed by its effect.


 * Light of Intervention: While this card is on the field you cannot flip a monster face-down with "Book of Moon"...


 * Magical Scientist: If the Fusion Monster is flipped face-down with "Book of Moon"... the effect is reset and the Fusion Monster does not go back to the Extra Deck, and is not prohibited from attacking your opponent's Life Points directly.


 * Mist Archfiend: If this card is turned face-down by "Book of Moon", etc. Chained to its effect, it will still be destroyed and its controller will take 1000 damage.


 * Moisture Creature: If you activate the effect of "Moisture Creature" and your opponent chains "Book of Moon" to the effect, the effect still resolves and all Spell and Trap Cards on your opponent's side of the field are destroyed.


 * Montage Dragon: If "Montage Dragon" is flipped face-down by "Book of Moon", etc., when it is flipped face-up its ATK is 0.


 * Ninja Grandmaster Sasuke: If "Ninja Grandmaster Sasuke" attacks a face-up Defense Position monster, and you flip it face-down during the "Battle Step" with "Book of Moon", the monster is face-down at the start of the Damage Step so "Ninja Grandmaster Sasuke" will not destroy it with his effect.


 * Offerings to the Doomed: If your opponent chains "Book of Moon" to flip the target of this card face-down, the monster is not destroyed and you will skip your next Draw Phase.


 * Ojama Delta Hurricane!!: If your opponent chains "Ring of Destruction" or "Book of Moon" to "Ojama Delta Hurricane!!", and one of the Ojamas is destroyed or flipped face-down, "Ojama Delta Hurricane!!"'s effect still resolves.


 * Ojamuscle: This card targets 1 face-up "Ojama King". If "Book of Moon" is chained to flip the targeted "Ojama King" face-down all the other "Ojama" monsters are destroyed, but no ATK increase is given.


 * Possessed Dark Soul: You cannot gain control of face-down monsters with this card's effect, so the opponent may chain "Book of Moon" selecting a Level 3 or lower monster and they will keep control of it.


 * Raging Cloudian: The "Cloudian" monster Special Summoned with "Raging Cloudian" cannot be targeted by "Book of Moon".


 * Rampaging Rhynos: If you activate the effect of a face-up "Rampaging Rhynos", and "Book of Moon" is chained to this effect, the face-down "Rampaging Rhynos" will still move.


 * Sakuretsu Armor: If the turn player chains "Book of Moon" to "Sakuretsu Armor" to flip the attacking monster face-down, then the attacking monster is not destroyed by "Sakuretsu Armor".


 * Samsara Lotus: If "Book of Moon", etc., is chained to "Samsara Lotus'" damage inflicting effect and flips it face-down, the effect disappears.


 * Shadowslayer: If "Shadowslayer" attacks a face-up Attack Position monster, and the opponent activates "Book of Moon" so that his only monster on the field is now in Defense Position, a replay occurs, because "Shadowslayer" is now able to attack directly.


 * Shien's Spy: If you chain "Book of Moon" to "Shien's Spy" to flip the target face-down, the monster still switches to the opponent and returns in the End Phase as normal.


 * Shifting Shadows: If you control a monster that is targeted by your opponent's "Nightmare Wheel", and you flip it face-down with "Book of Moon", and control at least 1 other face-down Defense Position monster, you can activate the effect of "Shifting Shadows". However, afterwards you must tell your opponent which monster is targeted by "Nightmare Wheel".


 * Spellbinding Circle: The Battle Position of a monster targeted by this card can still be changed by card effects, such as "Book of Moon"...


 * Spirit Reaper: "Spirit Reaper" is only destroyed by its own effect if it is face-up on the field when the effect designating it as a target activates, AND after the effect designating it as a target resolves. If you Special Summon "Spirit Reaper" with Monster Reborn, or flip it face-down with "Book of Moon", or flip it face-up with "Book of Taiyou", it is not destroyed...


 * Spirit of the Pot of Greed: "Spirit of the Pot of Greed" must be face-up on the field to resolve its effect; if "Book of Moon" is chained to "Pot of Greed" or to the effect of "Spirit of the Pot of Greed", "Spirit of the Pot of Greed"'s effect is negated.


 * Synchro Strike: You cannot target a Synchro Monster that was turned face-down by “Book of Moon”, etc., when it is later Flip Summoned.

Judge List Rulings

 * Spirit Reaper: If you Special Summon "Spirit Reaper" from the Graveyard with "Premature Burial" then, since "Spirit Reaper's" self-destruction effect does not begin a Chain, it will immediately destroy itself before you get a chance to activate something, like "Book of Moon", to save it.

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 * Zombie Master: "Zombie Master's" effect is a Spell Speed 1 effect, so you can't chain it to a Spell Speed 2 effect like "Book of Moon", "Bottomless Trap Hole", "Torrential Tribute", "Compulsory Evacuation Device", ect.