If I target a unit with Deflect and my opponent counters my spell, do I still have to pay the Deflect cost?

Ruling: Yes, you pay for Deflect when you choose targets, which happens when the spell is put on the chain. If the spell is countered afterward, you've already paid the Deflect cost.

Sequence:

• You cast the spell and put it on the chain
• You choose targets and pay Deflect costs at this time
• Opponent has opportunity to counter the spell
• If countered, you've already paid Deflect

Nuances:

• Some spells like Falling Star/Icathian Rain use "do this:" wording, which creates reflexive triggers that choose targets at resolution rather than when cast. For these spells, the opponent would need to counter before you pay for Deflect.