Magician's choice is a method by which a magician makes the volunteer from the audience appear to be choosing from two options, while secretly the magician makes the decision:
Magician: Here are two boxes--choose one, left or right?
Volunteer: The left.
Magician: All right, you want to eliminate the one on the left, then?
Volunteer: Yes.
Magician: Okay, my assistant will take that one away. Now, with the remaining box, watch as I...
Magician: Here are two boxes--choose one, left or right?
Volunteer: The right.
Magician: All right, you've chosen the one on the right. Assistant, please take away the other box. Now, with the remaining box, watch as I...
You think you chose, but you had no control at all. Magic is like politics, sometimes.
Update 2020-02-28: Just came across this video that shows it in use: https://www.tiktok.com/@justjoshinmagic/video/6798147218994990341