Do you get a point instantly when you conquer a battlefield? Can a move to an empty battlefield be reacted to? If that reaction kills your unit, do you get the point?

Yes, you score a point instantly when you conquer a battlefield. Here is the breakdown of how these mechanics interact based on the official rules.

1. Do you get a point instantly when you conquer a battlefield?

Yes. According to FAQ #6376, you score a conquer point immediately when you take control of a battlefield (after the showdown/combat resolves). This scoring happens as part of the process of establishing control, not at the end of the turn.

2. Can a move to an empty battlefield be reacted to?

It depends on how the move is performed.

• Standard Move: According to FAQ #6337, a standard move by itself does not open a chain, so it cannot be reacted to.
• Spell or Ability: If the move is performed via a spell or activated ability, a chain is opened, and players may play reactions.
• Triggered Effects: If any effect triggers during the movement, that effect opens a chain, allowing for reactions.

Note that moving to an empty battlefield initiates a "showdown" (Rule 447.1). While the move itself might not open a chain, the resulting state transition into a showdown allows players to play actions or reactions to start a chain (FAQ #6170).

3. If a reaction kills your unit, do you get the point?

No. You do not get the point if your unit is killed before control is established.

The sequence of events is governed by the rules for establishing control and scoring:

1. Showdown/Combat Resolution: The game determines the result of the showdown (Rule 461.3).
2. Establishing Control: If you have units remaining at the battlefield after the showdown, you establish control (Rule 461.5).
3. Scoring: Establishing control results in a "Conquer" if you have not yet scored that battlefield this turn (Rule 461.5.d). At this moment, you gain the point (Rule 466.1).

If a reaction played during the move or the resulting showdown kills your unit, you will not have units remaining at the battlefield to establish control, and therefore you will not score the point.

Note: I could not fully verify this ruling against the retrieved rules.