Making movies is definitely a serious business, but that doesn't mean you can't have fun on the set as well. We get a small glimpse at some of the on-set shenanigans in a new gag reel from the Lionsgate comedy Middle School: The Worst Years of My Life. This video features Andy Daly as Principal Dwight showing Adam Pally's Mr. Teller the various contraband students have in their lockers, although he opens the wrong locker in this sequence, forcing him to start over. We also get a glimpse at Lauren Graham, as she knocks over a house of cards, and Griffin Gluck goofing around with Efren Ramirez.

The New York Times best-selling series by James Patterson breaks all the rules when Middle School: The Worst Years of My Life arrives on Digital HD December 20 and Blu-ray (plus Digital HD), DVD, and On Demand January 3 from Lionsgate and CBS Films. This hilarious, family-friendly leap from the page to the big screen stars Griffin Gluck (Batman vs. Robin) alongside Lauren Graham (TV's Gilmore Girls), Rob Riggle (The Hangover), Thomas Barbusca (TV's Wet Hot American Summer: First Day of Camp), Andy Daly (Semi-Pro), Adam Pally (Dirty Grandpa), Isabela Moner (TV's 100 Things to Do Before High School), Isabella Amara (The Boss) and Alexa Nisenson (TV's Constantine).

Rafe has an epic imagination...and a slight problem with authority. Both collide when he transfers to a rule-crazy middle school. Drowning in do's and don'ts, Rafe and his best friend Leo hatch a plan to expose the principal by breaking every rule in the school's Code of Conduct. As the principal strikes back, Rafe's world, at home and at school, explodes into hilarious chaos (both real and imagined) in this laugh-filled family comedy based on James Patterson's best-selling book series. Middle School: The Worst Years of My Life opened in theaters this past October, and while it only took in just over $20 million at the box office, it only cost $8.5 million to produce.

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The Middle School: The Worst Years of My Life home entertainment release special features include four behind-the-scenes featurettes, a hilarious gag reel plus four deleted scenes, including one hilarious animated sequence. Middle School: The Worst Years of My Life will be available on Blu-ray and DVD January 3 for the suggested retail price of $39.99 and $29.95, respectively. Middle School: The Worst Years of My Life is directed by Steve Carr with screenplay by Chris Bowman & Hubbel Palmer and Kara Holden. The film is executive produced by James Patterson and Steve Bowen, with Leopoldo Gout and Bill Robinson serving as producers.

While we don't see her in the gag reel, this film marks the major studio debut of Isabela Moner, who may be on her way to super-stardom. She will next be seen in the highly-anticipated summer blockbuster Transformers: The Last Knight, which is set for release on June 23, alongside Mark Wahlberg. It remains to be seen if Lionsgate has plans to adapt the other three novels in James Patterson's best-selling Middle School series. While we wait for more on the future of this potential franchise, take a look at this gag reel from Middle School: The Worst Years of My Life below.