For Falling Star, do you pick targets on cast or on resolution?

Ruling: You pick targets on resolution. The spell creates reflexive triggers that go on the chain after the spell resolves, and targets are selected when those triggers are added to the chain.

Sequence:

• Falling Star is cast and goes on the chain
• Opponent can respond to the spell itself (e.g., with Deny to counter it)
• Falling Star resolves and creates two reflexive triggers
• The two reflexive triggers go on the chain and targets are selected at this point
• Opponent can now respond to the triggers after knowing the targets (e.g., with Hidden Blade)

Nuances:

• The two instances of damage are not spells themselves, so they cannot be countered by Deny once on the chain
• The reflexive triggers do trigger Deflect because Deflect triggers on both spells and abilities targeting
• Most opponents will wait until the reflexive triggers are added to respond, unless they want to counter the spell itself or restrict target choices