If I play a spell card with Repeat and my opponent Defies it, can I use Repeat to play it again, or does Defy prevent me from playing it entirely?

Ruling: When you cast a spell with Repeat, you must choose whether to use Repeat at the time of casting, before your opponent can respond. If you choose to Repeat and your opponent Defies the spell, the entire spell (including the repeated portion) is countered. You cannot choose to Repeat after a Defy.

Sequence:

• Declare you are casting the spell
• Choose whether to pay the Repeat cost as an additional cost
• Finalize the spell on the chain
• Opponent can now respond with Defy
• If Defied, the entire spell (including any Repeat) is countered

Nuances:

• Repeat is an optional additional cost paid before finalizing the spell, not a separate spell or ability
• Repeat extends the spell's effect box but does not create a second spell
• You cannot wait to see if your opponent Defies before deciding to Repeat