Tyler Perry Sued -- Screenwriter Claims Credit For 'Temptation' Movie ... On Purpose

Tyler Perry's 'Temptation' has been called everything from "beyond dumb" to "flamboyantly bad" -- yet a small-time screenwriter is suing, claiming Perry jacked the universally panned script from him.

It's the classic Hollywood sob story ... a man from Gary, Ind., says Perry stole his idea for "Temptation: Confessions of a Marriage Counselor," which didn't wow critics, but did rake in $49 million.

In the suit, William James says the plot is similar to "Lovers Kill," which he wrote in 2009. The lawsuit is light on details ... it just says both films center on a married couple ... the wife is tempted by another man, and the affair ruins the marriage.

Apparently James hasn't seen "Unfaithful" ... "Legends of the Fall" ... "The English Patient" -- need we go on?

But here's the best part: James doesn't even know for sure that Perry ever saw his screenplay -- in the suit, he claims he gave a copy to "an associate" of Oprah Winfrey, hoping it would make it to Perry.

Reps for Perry and Lionsgate ... the movie distributor, also named in the suit ... had no comment.