When Carnivorous Snapvine is played and its Focus effect triggers, can the turn player play an Action spell before the trigger resolves, or can only Reaction spells be played in response?

Ruling: When a unit like Carnivorous Snapvine is played and its effect triggers, that trigger goes on the chain immediately. Only Reaction spells can be played in response to that trigger - Action spells cannot be played until the trigger resolves. The turn player has priority to play Reactions first.

Sequence:

• Snapvine is summoned
• Snapvine's Focus trigger goes on the chain immediately
• Only Reaction spells can now be played in response
• Turn player has priority to play Reactions first
• After all players pass, the trigger resolves

Nuances:

• Dealing damage to a unit before combat does not reduce the damage it deals - a unit with damage on it still deals damage equal to its full Might value
• Units only heal after combat (Showdown) resolves or at end of turn, not immediately after taking damage
• All units heal at these timing windows, not just units that were in Showdown