Learn English – A word or term for: “in another person’s body”

This sounds like a special case of the argument from authority.

I'd love to help, but I'm just not sure what a pre-enactment would be. Are you saying a pretend period before something actually happens? Then, in my opinion, it would be better to call it a rehearsal or a dry run.

But I would need to know more. You say that, for instance, a fictional movie about the future might include a "pre-enactment" of World War III. It's not really a "pre-enactment," since we don't know for sure that World War III will happen (and let's hope it doesn't). What you describe is speculative, so I'm troubled by the use of "enactment."

EDIT: This post was made before the author updated his original query to include a discussion of my ideas about 'rehearsal' and 'dry run.'

But you do raise an interesting word challenge: is there a word that describes a staging of things that we know for certain are going to happen?

For example, in the Seinfeld episode "The Non-Fat Yogurt," an integral part of the plot was the mayoral election between incumbent David Dinkins and challenger Rudy Giuliani. Since the episode was shot prior to the election, but would be aired after the election, two endings were shot: one with Dinkins being re-elected, the other (which was aired) with Dinkins losing to Giuliani.

So what would be the word that describes the two scenarios which were filmed prior to the election, an event which WAS guaranteed to happen? Is there even a word to describe that?

SECOND EDIT: I'm still troubled by your latest example. What happens after death is still entirely speculative. It could very well be that nothing happens after death. So to use the word 'enact' to describe a portrayal of what happens after death, in any sense, is to me inaccurate, because the event itself is not guaranteed to happen. But in that specific example, I'd call it a "speculative portrayal" rather than a pre-enactment.

I'd love you to come up with an example I can get behind...and then I'll get back to work on your behalf!

THIRD EDIT: Your new romantic comedy example certainly describes a rehearsal or a dry run (at least to me).