What happens if a character's declared action becomes impossible?

Question

What happens if a character’s declared action becomes impossible before they can attempt it in the attack phase? Do the core rules support the idea that they get to pick a different action, or perform a similar action, or do they effectively lose the ability to act in that round?

For example, if a character wants to shoot someone but the target suddenly disappears from this plane of existence, is that character still forced to spend her round shooting at nothing, or can she now opt not to pull the trigger?

Since "shooting at the location where the target recently was" isn't impossible, a better example might be if a character is disarmed before they can use a weapon. Can that character do nothing but follow through with their declared weapon-attack, albeit pantomimed?

Considering actions other than attacks, if someone declares that they'll run across a room and through an open door, but the door is closed and bolted shut before their turn in the initiative order, are they then forced to run up to the door, or would they be allowed to remain in place since their intention is now impossible?

Notes

• This is setting aside the rules for aborting an attack in favor of a defensive action.
• It makes sense that changing an attack's target during the attack phase would not be allowed, since that would give the attacker an unfair advantage in surprising a higher-initiative target who did not anticipate being attacked and thus had no defensive action prepared.

Answer 1

The action is wasted, at least as it was intended

The major basis for that statement is that combat rounds in V:tM are three-second slices of time with simultaneous actions. The initiative order is used both to make that more manageable (it's hard to track and interact with 10 characters operating at the same time!) and to simulate the advantages held by characters who are faster than others. Consider this excerpt:

Although you declare your character’s action now [this is the Initiative phase] (including stating that your character delays her action to see what someone else does), you wait until the attack stage to implement that action. At this time, you must also state if any multiple actions will be performed, if Disciplines will be activated, and/or if Willpower points will be spent. Characters declare in reverse order of initiative, thus giving faster characters the opportunity to react to slower characters’ actions. (V20 Core Rulebook, page 271)

Emphasis mine. It is explicit that the purpose of declaring actions in reverse initiative order is to allow faster characters to undercut slower characters' efforts. It doesn't fit too well with that to allow a slower character to declare an action, have it thwarted, and then freely choose a different action all in the same 3-second window.

Portions of an action may still be possible, as in the "intending to run through a door which is suddenly closed". You may not be able to run through the door, but I would almost certainly rule that you still run up to it before it slams shut in your face.

Narration is important. This is a game under the Storyteller system! A situation like the one described in the question, while not too common in my experience, allows for tense and exciting encounters.

When two vampires are fighting in the Deadlands, one doesn't disappear through the Shroud back to the living world and then after a pause their opponent starts shooting at where their target used to be in frustration. It all happens at once, and the disappearing character acted just a hair more quickly than the other one. The narrative-focused Storyteller system is probably better served by something like:

Lucretia levels her pistol at Augustus and pulls the trigger three times, with three precise, controlled motions. But as the bullets fly towards Augustus, he seems to fade away. In the fraction of a second it takes the bullets to reach Augustus' former position, there is nothing there to hit!