There’s a comfortable class-reunion vibe to the gangland comedy "Stand Up Guys." Pretty much everyone in the entire acting company reprises roles they’ve played to perfection before.

You’ve got Christopher Walken spot-on as Doc, a laconic hit man. Here’s Al Pacino gleefully desecrating his "Scarface" roles as Val, a cartoonish and more over-the-top-than-usual bank robber. Alan Arkin rounds out the crew as Hirsch, another grumblesome lion in winter, this time a retired getaway driver on one final fling.

‘STAND UP GUYS’ Rated: R Opens today

The casting gives us three men on base even before Julianna Margulies appears as a kindhearted hospital nurse, "Breaking Bad’s" Mark Margolis plays a murderous villain and Lucy Punch, comedy’s go-to harlot, pops up as a ditzy hooker.

What could go wrong? Not much, if you’re in the agreeable mood this enjoyable film aims to kindle. The story template is comfortably familiar, a mob variant on "The Last Detail."

Walken’s creaky triggerman, an old confederate of Pacino’s, meets him at the prison release gate, and the pair celebrate his freedom by getting drunk, getting in fights and getting laid. Pacino, who has a mob contract on his head, is aware that his old crony Walken is probably going to kill him, but sees no reason why that should spoil their night.

There’s nothing groundbreaking in the way the story unfolds. There’s a damsel to be rescued, dishonorable younger thugs to be taught respect, a hot muscle car to be red-lined through cop chases, and if you don’t see the Viagra jokes coming a mile away, check your bifocals.

It’s unassuming stuff, directed with workmanlike diligence by Fisher Stevens. He knows he doesn’t have to get fancy with actors of this caliber. Just turn on the camera and turn them loose.

They make mild gags funnier than they have any right to be. A sequence at a bar where Pacino grinds up Walken’s heart medication and snorts it through a straw had me grinning in admiration. The idea is so-so, the execution priceless. By contrast, the go-for-broke jokes (like the sight gag of Val in the emergency room with drug-induced priapism) feel strained. Some of the best passages simply plunk the old pros down in a diner and let them talk, volleying dialogue back and forth like jai alai champions.

I can’t argue that performers the stature of Pacino, Walken and Arkin don’t deserve better material, yet it’s so nice to have them on screen together I’m in no mood to quibble.