Can you win by conquest if you leave a battlefield after scoring it, and can you score/conquer the same battlefield multiple times in one turn?

Question

Accepted Answer

Yes — scoring (including by Conquer) happens when you gain control; leaving afterwards does not undo the score you already earned. You cannot Score/Conquer the same Battlefield more than once in the same turn (a Conquer requires the Battlefield be one you have not yet Scored this turn).

A Conquer scores immediately when you gain Control of a Battlefield you have not yet Scored this turn, and that Score (and any point gained from it) stands even if you later leave the Battlefield. You may not Score/Conquer the same Battlefield multiple times in one turn [464] [466.2.c]. To gain the Winning Point via Conquer you must meet the special final-point condition for Conquer (you must have Scored every Battlefield this turn) — otherwise Conquer that would be the final point instead causes a draw-a-card effect per the Winning Point restriction [466.1.b].

You Conquer a Battlefield by gaining Control of it (Conquer is defined as gaining Control of a Battlefield you have not yet Scored this turn) — that action is the Score event and is processed immediately [464]. When that Score occurs, the game attempts to have you Gain up to one Point based on your current score and the Winning Point restrictions; whether you actually Gain the Winning Point from that Conquer depends on the special rule for the Winning Point (Conquer-based final point requires you to have Scored every Battlefield this turn) [466]. After the Conquer/Score resolves and any Points or triggers are applied, later actions that remove your Units from the Battlefield (causing it to become Uncontrolled) do not retroactively erase the Score that already occurred — the Score already happened when you gained Control [461] [323]. Because Conquer is explicitly defined as gaining Control of a Battlefield you did not yet Score this turn, you cannot Conquer/Score that same Battlefield again later in the same turn (and Score-triggered abilities on that Battlefield only trigger when it is Scored) [464] [466.2.c].

If a Conquer would be the final point but you have not Scored every Battlefield this turn, the Conquer does not grant the Winning Point; instead the rules instruct the player to draw a card for that attempt (see 466.1.b.2). In multiplayer/2v2 formats, special rules about which Battlefields are eligible or how the final point is adjudicated can alter whether a Conquer can produce the Winning Point — see format-specific rules (example: 2v2 adjustments in [484.8.f.1]). If a card effect attempts to treat a Conquer as occurring for trigger purposes without actually granting Control (see clarifications like the one discussed in [FAQ:unleashed#23]), that may let certain triggered abilities see a Conquer event without an actual Score — but actual gaining of Control is required for a true Conquer Score as defined in [464].

Scoring happens at the moment you Score a Battlefield. Conquer is defined as gaining Control of a Battlefield you have not yet Scored this turn, so the Score occurs when you establish Control via Conquer [464]. When a Score is processed the game immediately attempts to have you Gain a Point according to the Winning Point rules; for Conquer that includes the extra restriction that to Gain the Winning Point the player must have Scored every Battlefield this turn — otherwise a Conquer that would be the final point causes the player to draw a card instead of gaining the Winning Point [466] [FAQ:unleashed#12]. Because the Score is resolved at the time you gain Control, subsequent events (like you leaving the Battlefield and it becoming Uncontrolled) do not retroactively undo the Score or the point(s) already gained from that Score [461] [323]. Finally, Conquer explicitly requires the Battlefield be one you have not yet Scored this turn, and Score-triggered abilities at that Battlefield only trigger when the Battlefield is Scored; therefore you cannot Score/Conquer the same Battlefield more than once in the same turn [464] [466.2.c].