Rulings

• 2020-01-24
  An ability that triggers when a creature becomes the target of a spell resolves before the spell that caused it to trigger. It resolves even if that spell is countered.
• 2020-01-24
  Players can cast spells and activate abilities after the triggered ability resolves but before the spell that caused it to trigger does.
• 2020-01-24
  If a spell targets Tectonic Giant more than once, its ability triggers only once.
• 2020-01-24
  You choose which of the exiled cards you'll be able to play while the ability is resolving. You can't wait to pick one later. The other card remains in exile.
• 2020-01-24
  Tectonic Giant doesn't change when you can play the exiled card. For example, if you exile a sorcery card, you can cast it only during your main phase when the stack is empty. If you exile a land card, you can play it only during your main phase and only if you have an available land play remaining.
• 2020-01-24
  Playing an exiled card causes it to leave exile. You can't play it multiple times.
• 2020-01-24
  If you don't play the exiled card that you chose, it remains in exile with the card you didn't choose.