flim-flam
play a joke on
play tricks
trick **
fob
fox ***
pull a fast one on
play a trick on

Maybe they were playing a trick on him to see what he would do.

I don't know why mind and body play such tricks but they do.

When the two boys played tricks on him, he'd always get the better of them.

Time could play good tricks with the mind, as well.

He was a great one for playing tricks on people too.

I thought a long day in the sun must be playing tricks on my mind.

For a moment, he thought his eyes had been playing tricks on him.

I ask myself sometimes whether my eyes may be playing tricks.

At first I thought the sun was playing tricks on my eyes.

His mind was playing tricks on him, and why not?