Ryan Reynolds, who has made a career of entertaining frat boys in films like “National Lampoon’s Van Wilder” and “Harold and Kumar go to White Castle,” plays the same character over and over again. And over. Again.

But it works.

In “Just Friends,” however, Reynolds isn’t his typical character ” at least in the beginning. Instead, he starts out in a really crappy fat suit (you can see the glue on his chin!). In it, he does just about everything he can to mimic the success of the character Napoleon Dynamite ” but fails miserably.

He is incapable of being a true nerd. His destiny as a character actor proves he’s too sarcastic and full of himself to pull it off.

The shallow skeletal structure of “Just Friends” is this: It’s 1995 in New Jersey. Chris Brander (Reynolds) is a fat loser who is best friends with the hottest, coolest girl in high school, Jamie Palamino (Amy Smart) who always falls for jerks. Jamie tells Chris everything, and he is in love with her. But he is forever destined to be in the “friend zone.”

Fast-forward 10 years. Chris is a hockey player and successful Hollywood talent agent (I don’t get it either). He’s working to sign pop singer Samantha James (Anna Faris), a hilarious spoof on Britney Spears.

Through unfortunate and unbelievable circumstance, Chris ends up home in Jersey for the first time in 10 years and brings Samantha along.

Chris sees Jamie working at a bar. Jamie sees Chris. They click. He’s a turd. She’s hard to read. Blah, blah, blah. They end up making out in front of holiday lights. Aww. Barf.

But with unexpected, funny quips like, “You’ll always be fat to me, Chris,” and gut-grabbing physical comedy, it’s a good rental. Or if Ma passes you $20 under the Thanksgiving table, go for it. You’ll have a good, if shallow, laugh.