This card affects monsters, Spell Cards, and Trap Cards controlled by both players. You cannot activate this card during the Damage Step.It does not change cards which 'double', 'half', or 'reduce to 0' the ATK or DEF of a monster. This card only affects increases and decreases of a defined value, such as +200 (which becomes -200) or -500 (which becomes +500). If a card gives a monster +100 ATK, and ' Reverse Trap' is activated, that monster now has -100 ATK instead.They were previously considered official and can still be correct, as long as they follow the official gameplay rules, or unless Konami has issued a ruling that says otherwise. These TCG rulings were issued by Upper Deck Entertainment and have since been deemed unofficial by Konami. Afterwards, if during the same turn another Spell Card, Trap Card, or monster effect is activated, ' Light and Darkness Dragon' effect won't activate. When it does, it will gain 500 ATK and DEF. If the effect of ' Reverse Trap' is being applied, the effect of ' Light and Darkness Dragon' that negates the activation will only activate once time.Also, the effect that increases ATK by half the ATK of the opponent's monster during damage calculation, reduces ATK by half the ATK of the opponent's monster instead. If the effect of ' Reverse Trap' is being applied, the effect of ' Metalmorph' that increases 300 ATK and DEF, reduces 300 ATK and DEF instead.In the end, ' Flash Assailant' ATK will be 6000. In this case, if you have 5 cards in your hand and your Life Points is less than your opponent's, if ' Reverse Trap' is activated, the ATK of ' Flash Assailant' becomes 4000 by doubling its ATK by the effect of ' Megamorph', then instead reducing the ATK of ' Flash Assailant' by 2000, it ATK is increased by 2000. If ' Flash Assailant' is equipped with ' Megamorph', the effect of ' Megamorph' reduces its ATK in half or doubles its ATK, then the effect of ' Flash Assailant' reduces its ATK.Thus, you cannot activate ' Reverse Trap' during the Damage Step. ' Reverse Trap' is not an effect which increases or decreases the ATK or DEF it is an effect which affects effects which increase or decrease ATKs or DEFs.No damage will be inflicted in that case.

Black-Winged Dragon: If Reverse Trap is activated, the ATK of Black-Winged Dragon will increase for each Black Feather Counter on it and an opponent’s monster targeted by the effect will have its ATK increased.

Yugioh uno reverse