Who came up with this idea?The Man of Steel reduced to sharing screen time with Richard Pryor and his painfully unfunny mugging? What the fuck?
Pryor's a computer genius who synthetically creates Kryptonite for bad guy Robert Vaughn, adding tar because he's missing an element. The new Kryptonite turns Superman into a louse. He starts to put the moves on Lana Lang (Annette O'Toole) and every other woman. and appears to have a drinking problem. He also doesn't shave, and sneers a lot, so you know something's up. When Superman's not clean cut, strange things are indeed afoot.
It all comes to a head when Superman splits into two people and they fight each other. In a junkyard. Superman beats Superman (or Clark beats Superman or whatever), then goes after Pryor and Vaughn, who've set up a bigass supercomputer in the Grand Canyon. Superman fights computer and wins. Yay. Everyone goes home happy.
Except for the audience.
Superman III is the distant cousin of Batman & Robin, an unsuccessful blend of superheroes and would-be comedy. Action played for laughs. Horribly unfunny and devoid of action, this clipped the franchise (Superman IV would bury it completely).Just watch the first one over.