Denzel Washington starts in "Roman J' Israel, Esq."

This is a confusing movie that doesn’t know what it wants to be about a character who doesn’t know who he is.

Part courtroom drama, part character study and part thriller, “Roman J. Israel, Esq.,” a movie that’s serviceable only because of star Denzel Washington’s performance.

Washington plays Roman, an odd duck of an attorney who finds himself at loose ends.

For years, Roman has been the assistant to an attorney who helps those in need. Now a tragedy forces Roman into the courtroom and out into the world.

And it’s not just Roman’s awkward ways and possible connection to the autism spectrum that make him someone others look upon as “different.” He also seems stuck in the 1970s in his appearance and his attitude, including his approach to community activism.

His new boss George Pierce (Colin Farrell) sees potential in Roman’s determination and smarts. Roman can quote the rules of law from memory —he’s intelligent and savvy in his own way. But he’s not savvy enough to stop from becoming involved in a situation that’s, shall we say, highly questionable ethically.

The screenplay of writer/director Dan Gilroy, who wrought the far superior “Nightcrawler,” wanders all over the place.

First, there’s a little bit of the character study, even though we don’t really learn enough about Roman for this to be categorized as such. Then there’s a little bit of thriller, but not enough to establish tension or truly engage the viewer.

Then we get a little bit of courtroom/law office drama, but not enough to make the movie a memorable one.

It’s fun to watch Washington, though, especially when he becomes conflicted about the choices he has made. His character’s scenes with a woman activist (Carmen Ejogo, “Alien: Covenant”) don’t add much to the proceedings.

Is Roman afraid of romance? Is he immune to the opportunity for intimacy? We never learn. So a relationship that could have shed light on his character falls flat and feels unnecessary.

This could have been a movie as enjoyable as “Nightcrawler” if it had been more condensed. As it is, the overly long two-hour running time does its character no favors.

It’s Washington’s talent of inhabiting a character that makes this film worth seeing. Had a lesser performer been the lead, it wouldn’t have reached even so-so status.

As it is, this is an OK way to spend two hours — but it’s just OK, worth the price of a bargain night or matinee. Just don’t expect to see anything that will be mentioned in the coming awards season.