Why wasn't princess Leia executed immediately?

Because she knew where the plans for the death star were and Vader wants to get them back before the rebels work out how to blow the thing up.

It wasn’t in the script!

Vader couldn’t bring himself to kill his own daughter.

Of course @SQUEEKY2 has the real-world answer. But in-story, it’s because they want to (1) find the stolen Death Star plans, (2) learn the location of the secret Rebel Alliance base, and (3) show off their evil by forcing her to witness the destruction of her home planet. (It’s not Vader being squeamish, because at that point in the story, he doesn’t yet know that Leia is his daughter.)

It certainly would have made the movie a lot shorter.

Where’s the adventure if the hot babe is eliminated 3 minutes into the first reel? Besides, fictional evil is always enhanced with a threatening possibility of upcoming torture.

Because it doesn’t serve to advance the plot to kill her immediately. If she were going to be killed a few minutes into the movie, then why bother having her there at all?

It’s the same as why doesn’t the Bond vilain just kill 007 as soon as he’s captured instead of talk talk talk followed by some contrived torture from which he (of course) manages to free himself?

Basically the same situation. A quick efficient death does not serve to further the plot. And that’s what movies are all about.

Delaying the death of the hero (heroine) is a time honored plot device which is as ubiquitous as the upset scattered fruit cart in the chase scene of an adventure movie.

Have you ever noticed how many fruit carts are so conveniently located in the most awkward places so that they will certainly be turned upside down in the course of the chase sequence with produce flying everywhere?

…edited .

Plot

For the same reason why Imperial Stormtroopers can’t hit a standing target from a few feet away – it’s not convenient to the plot.

Because after THX1138 George Lucas thinks you’re stupid.

Clarification:

I am not suggesting Lucas had yet started to sucker the fimlgoing public by the time THX had been produced. It obviously began after.

THX was a brilliant product that delivered so much movie feel especially considering the budget.

I am of course talking about the original cut, devoid of Lucas’ trademark digital fiddling found in the director’s cut (does the lizard really have to have wings? what the hell is C3-PO doing making a cameo?).

THX 1138 really does show the potential Lucas had at one point.

The concept of giving over to The Darkside as selling one’s soul or talent (in this case for marketing and mass appeal) is just too delicious a parallel to ignore.

I believe it was Garry Kurtz (who stopped working with Lucas after The Empire Strikes Back) who said that by then toy marketing was dictating the story writing.

@Darth_Algar “For the same reason why Imperial Stormtroopers can’t hit a standing target from a few feet away – it’s not convenient to the plot.”

Actually, it was quite convenient to the plot; the Empire’s plot

I figured they went to the same range training course many of my officers went to. Poor sorry SOB’s couldn’t hit the broad part of a barn from the inside.

@jerv

Ok.