It’s hard to make prison funny.

Beyond dropped soap in the showers and mystery slop in the cafeterias, the realities of prison are too bleak and serious to inspire a laugh.

“Up the River” and “Two-Way Stretch” are two classics that took place in prison and were funny at the same time, a difficult feat indeed. Other films, such as “Half Baked,” rely too heavily on tales of rape.

The clichéd “Let’s Go to Prison” fits into the latter category by stereotyping the incarcerated comedy to the point of no return.

It’s based loosely on “You Are Going to Prison,” a 1994 nonfiction book written by several inmates under the collective pen name Jim Hogshire. The movie incorporates some of the book’s facts early on – it costs $54 a day to keep a man in prison – then loses interest and gets back to its primary task, which is to tell a ludicrous and juvenile story and make fun of male rape.

Dax Shepard plays John Lishitski, whose last name signals the quality of humor on display here. He’s a repeat offender out to take revenge on the judge who puts him in jail over and over again, but is forced to target his son instead after the dad dies. John frames the younger Nelson Biederman (Will Arnett) for a botched robbery, and then – to get closer – gets himself incarcerated in the same cell with Biederman.

These two protagonists are hardly an inspired comedy team, and when a crew of flatly-developed supporting characters is added to the equation, things really fall apart.

There’s Barry (Chi McBride), a big-boned inmate who “likes soft things,” Lybard (Michael Shannon), the head of the white supremacist gang whom Nelson accidentally disses and Officer Shanahan (David Koechner), who takes any opportunity to make a buck off the inmate’s fighting.

Of course, there’s a shower scene, where Barry develops amorous eyes for Nelson. Barry ends up taking Nelson back to his cell, decorated with draping fabric and candles, and offers him his eternal love and wine made in a toilet.

Director Bob Odenkirk, one half of the “Mr. Show” team, makes a cameo as Nelson’s ineffectual lawyer. He’s a funny writer and performer in his own right, but his time in the director’s chair could have gone a bit more smoothly. The film suffers from inelegant pacing, terrible acting and violence that’s a bit stronger than you’d expect from a comedy.

In “Let’s Go to Prison,” the elements of a dark comedy, prison satire and gross-out gags blend together like the slop ladled out for inmates at meal time.