If you haven't noticed, Effect Veiler is gaining a lot more popularity this format. So it is important for you all to know the proper rulings. Here we go:
1. This card will negate effects that activate or apply on the field. It will not negate an effect that activates in the Graveyard.
2. If you control the targeted monster when the effect of Effect Veiler resolves, the targeted monster's effect(s) will not be negated.
3. If the targeted monster is no longer face-up on the field when Effect Veiler's effect resolves, the targeted monster's effect(s) will not be negated.
4. If the effect of Effect Veiler resolves, and the targeted monster is then flipped face-down, its effect(s) will no longer be negated, even if it is flipped face-up again later that turn.
5. If you target Exiled Force with Effect Veiler and your opponent Tributes Exiled Force to activate its effect later in the turn, the effect of Exiled Force will be negated.
6. Chaos Sorcerer: If the effect of "Chaos Sorcerer" is activated (even if the effect is negated by another effect such as "Effect Veiler" or "Light and Darkness Dragon"), "Chaos Sorcerer" will not be able to attack during the turn.
1. The effect of "Effect Veiler" can only negate effects which activate on the field and effects which are applied on the field.
2. The effect of "Effect Veiler" cannot negate effects which activate in the Graveyard.
3. Suppose that "Exiled Force" is affected by the effect of "Effect Veiler". If "Exiled Force" Tributes itself to activate its effect, then its effect is negated.
4. 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.
So those are the rulings of Effect Veiler. Any questions feel free to ask down below.
Konami Gameplay FAQ: Duelist Revolution Sneak Peek -- Card Rulings (Version 1.0)
Konami Judge Program Forum: Chaos Sorcerer Effect being negated + declaring attack
FAQ: Effect Monster > Effect Veiler
Konami FAQ: If you activate the effect of a "Exiled Force" which is affected by the effect of "Effect Veiler", then is it negated?
Konami OCG FAQ: When resolving the effect of "Effect Veiler", if the targeted monster is face-down, then do you negate its effects?