345. If all players pass Focus without playing a spell or activating an ability, then the Showdown Closes.

345.1. If this Showdown opened as a result of Combat, proceed with the remaining steps of Combat to resolve the phase. See rule 441. The Steps of Combat for more information.

345.2. If this Showdown opened as a result of Contested being applied to a Battlefield without a controller, do one of the following:

345.2.a. If only one player’s Units remain at the Battlefield , and if that player does not already Control the Battlefield , that player establishes Control over the Battlefield . See rule 179. Control for more information on Control . See_rule_REF_446.1_DOT for more information on Conquering .
345.2.a.1. This results in a Conquer if that player has not yet scored that Battlefield this turn.
345.2.b. If two players’ Units remain at the Battlefield , Control cannot be established and the Battlefield remains Contested . This results in a Staged Combat . See rule 437. Combat for more information.
345.2.b.1. The player who applied Contested to the Battlefield will be the Attacker in the subsequent Combat.