If you score a point from a battlefield with Hold, then lose control and move a unit with a 'when I conquer' trigger back to that battlefield, does the conquer trigger activate?

Ruling: No, the conquer trigger does not activate. You may only conquer each battlefield once per turn, regardless of how you scored from it (Hold or Conquer).

Sequence:

• If you score from a battlefield in any way (Hold or Conquer), you cannot conquer that same battlefield again that turn
• Moving a unit back to a battlefield you've already scored from does not trigger conquer abilities
• You can retake control and start a showdown, but no conquering occurs

Nuances:

• Conquer abilities still trigger at 7 points when you would draw a card instead of gaining a point
• "Score" is the verb that describes what happens when you conquer or hold a battlefield - it usually means +1 point, except at 7 points when you draw a card instead
• Moving units to a battlefield you've already scored from can still start a showdown and let you retake control, just without the conquer trigger