In a surprise defense scenario (when a player moves a unit to an unoccupied battlefield and the opponent responds by moving a unit there with Ride the Wind), does the initial open showdown end immediately and combat start, or do players continue passing priority in the open showdown before combat begins?

Ruling: Players continue passing priority in the initial open showdown until both pass without starting a chain. Only after the open showdown ends naturally does combat begin.

Sequence:

• Player moves a unit to an unoccupied battlefield, starting an open showdown
• Opponent plays Ride the Wind, moving their unit to the battlefield (this stages a combat)
• Players can continue playing actions and passing priority during the open showdown
• Units do not gain attacker/defender designations yet during this open showdown
• Once both players pass without starting a chain, the open showdown closes
• During cleanup, the staged combat begins and units gain attacker/defender designations
• Combat proceeds normally

Nuances:

• Combat cannot start during a showdown - it requires a neutral open state (no items on chain and no showdown in progress)
• The patch notes clarification that "the current showdown will end and a second showdown will begin" is misleading - the showdown ends naturally through normal priority passing, not immediately
• The player who first applied contested status to the battlefield is the attacker; any units moved there afterward are defenders
• Abilities that trigger "when I attack" or "when I defend" trigger when combat begins and units gain those designations, not during the open showdown