Does Defy counter a spell based on its printed cost or the total cost paid including additional costs (like Rocket Barrage's additional cost or Accelerate)?

Ruling: Defy only looks at the printed cost of a card, not the total cost paid including additional costs like those from Rocket Barrage or Accelerate.

Nuances:

• This applies even in hypothetical scenarios where Defy could counter units with Accelerate costs
• Additional costs paid during activation do not affect whether Defy can counter the spell