Rulings

• 2019-01-25
  If a spell with an addendum ability is copied, the copy won’t give you the addendum bonus. This is because the copy wasn’t cast at all.
• 2019-01-25
  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. For example, if you cast Sphinx’s Insight during your main phase, you gain 2 life during its resolution, after you draw two cards.
• 2019-01-25
  Unbreakable Formation affects only creatures you control at the time it resolves. Creatures you begin to control later in the turn won’t gain indestructible or vigilance and they won’t get a +1/+1 counter.
• 2019-01-25
  Unbreakable Formation affects only creatures you control at the time it resolves. Creatures you begin to control later in the turn won't gain indestructible or vigilance and they won't get a +1/+1 counter.
• 2019-01-25
  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. For example, if you cast Sphinx's Insight during your main phase, you gain 2 life during its resolution, after you draw two cards.
• 2019-01-25
  If a spell with an addendum ability is copied, the copy won't give you the addendum bonus. This is because the copy wasn't cast at all.
• 2024-01-12
  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.
• 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.