Do Falling Star and Icathian Rain put multiple separate items onto the same chain or separate chains, and when exactly does targeting and damage happen with these spells?

Ruling: There is only one chain in Riftbound. Falling Star and Icathian Rain create multiple reflexive triggers that are placed as pending items on the same chain after the spell resolves. Targets are chosen and deflect costs are paid when finalizing these triggers to the chain, before they resolve.

Sequence:

• Falling Star is played and finalized to the chain
• Players can react
• Falling Star resolves, creating 2 reflexive triggers as pending items
• Targets are picked for both reflexive triggers
• Deflect costs are paid for each trigger targeting an enemy unit with deflect
• Players can react
• First trigger resolves, dealing 3 damage
• Players can react
• Second trigger resolves, dealing 3 damage

Nuances:

• Targets cannot be rechoosen once declared; if a target becomes illegal after selection, that trigger does nothing on resolution
• If Retreat is cast before targets are chosen, the opponent can choose different targets; if cast after targets are chosen but before triggers resolve, targeted units can be saved
• Players often shortcut by announcing targets immediately when playing Falling Star; if the opponent interrupts this shortcut before targets would be chosen, the Falling Star player can retarget (though there is some debate about the exact interpretation of tournament rules here)
• The original Falling Star spell does not target, so no deflect is paid for casting it; deflect is only paid when finalizing the individual triggers