Precognitive Perception
Instant
Draw three cards.
Addendum — If you cast this spell during your main phase, instead scry 3, then draw three cards.
"To control the present we must master the future."
Chris Rallis
Ravnica Allegiance (RNA)
• #45Rulings
Addendum abilities of instant spells apply while the spell is resolving, not immediately after casting it. If the spell is countered, you don't get the addendum bonus.
(wotc • 2024-01-12)
If an effect copies a spell with an addendum ability while it's on the stack, the copy wasn't cast at all, so you won't get the addendum bonus.
(wotc • 2024-01-12)
Rulings
Addendum abilities of instant spells apply while the spell is resolving, not immediately after casting it. If the spell is countered, you don't get the addendum bonus.
(wotc • 2024-01-12)
If an effect copies a spell with an addendum ability while it's on the stack, the copy wasn't cast at all, so you won't get the addendum bonus.
(wotc • 2024-01-12)