Can you retreat after capturing a battlefield (but not conquer), or conquer but then choose not to hold (retreat back)?

Ruling: You cannot avoid conquering if you end a showdown with only your units present at a battlefield you do not control (and haven't scored this turn). Units exhaust when they move to the battlefield to initiate the showdown, not when they conquer it.

Sequence:

• Units exhaust as a cost to perform a standard move to the battlefield
• Showdown occurs
• If only attackers remain at a battlefield you don't control, you must conquer and score 1 point
• Conquering does not give any special window or permission to move exhausted units

Nuances:

• You can move units from a battlefield if you have the ability to do so (e.g., through spells or other card effects)
• Standard exhausted units cannot move back without special effects