How did Luke disguise what he does

Question

There are spoilers about Star Wars: The Last Jedi in this question, be careful.

I first apologize for any wrongly used word or approximation as I am not a particular fan of Star Wars and I have seen each movie once a long time ago except for the last two, which I don't recall entirely.

For my question, it could go the other way as how did Kylo get fooled by an illusion (or clone ?)? From a guy who's pretty far and I'm guessing that's an understatement but have no idea how far.

Since he's a powerful force user I'm guessing he must have some kind of sensitivity to the force, can't he feel that the "force field" around Luke isn't the same? Or even the clone itself, I'm guessing the clone isn't perfect as well(movement speed, reaction time or something) or is it some kind of ultimate technique that draws every bit of strength you have (since we see Luke dissapearing right after)?

And for some clarity about the illusion, we see that Luke avoids being hit so that Kylo doesn't see that it's an illusion. But a few minutes before he touches his sister and even gives her something (the dice thingy that we see dissapearing a few moments later) so he can interact with his environment but only small interaction?

Answer 1

A running theory (can't remember where I heard it, sorry) is that Kylo Ren was too obsessed with his own desires to see the truth. Just moments before, he was espousing his "kill the past" philosophy to Rey, which means that he certainly wants to kill the man who he believed betrayed and tried to kill him. Luke appearing before Kylo when Kylo has a huge army at his control would be too good a deal for him to pass up in that moment.

As far as the mechanics of the trick, I don't think anything special was done to interact with Leia. I believe she was aware of the trick the moment he showed up (we've often been shown how the Skywalkers can feel each other through the force), or when he gives her a fake kiss on the forehead and fake dice to hold.

Answer 2

Think this is TBD. A lot of the Star Wars movies only began making sense after later movies provide explanation, or other writers in the unofficial expanded universe (now called legends) space fill in details themselves.

But at a guess, Luke may have been dead for a long time or might have been on the edge of dying when he did performed this feat. In some of the comic books, it is not clear if people sensitive to the Force can always discern a ghost in the Force for what it is.