First announced in October 2011, Dumb and Dumber To underwent a turbulent pre-production phase which included, at one point, Carrey withdrawing from the project, and Warner Bros. Pictures refusing to distribute the film.

[3][6] On June 15, 2017, the United States Department of Justice charged that money used to produce the film was stolen from a Malaysian government investment fund.

[9] For 20 years a catatonic Lloyd Christmas has been committed to a mental institution ever since he discovered Mary Swanson was already married at the end of the first film.

Fanny, who has taken the name Penny, is going to a KEN Convention in El Paso, Texas to give a speech on her father's life work.

He becomes increasingly annoyed with the duo, and attempts to kill them after they pull a near death-causing prank on him, although he ends up dying in a train collision.

Adele hears of the death from Travis's twin brother Captain Lippincott, a former military man who agrees to help her kill Harry and Lloyd.

They are invited to a seminar, but get into an argument when Harry discovers that Lloyd has developed a romantic attraction to Penny, having seen her photo earlier.

Fraida reveals that Penny's actual biological father is not Harry or Lloyd but their deceased high school friend, Peter "Pee-Stain" Stainer.

In a post-credits scene, Harry and Lloyd inadvertently toss milkshakes onto the windshield of Sea Bass, the trucker whom the duo had scammed in the first film, leading to him angrily bearing down on them in his truck.

A false advertisement for "Dumb and Dumber For" is then shown, with a camouflaged Captain Lippincott appearing from the advert and walking off-screen.

[23] Warner Bros.'s New Line Cinema division—which produced the first film and its prequel, Dumb and Dumberer: When Harry Met Lloyd—was given studio credit from Universal.

[24] Although Peter Farrelly confirmed the sequel was moving forward,[25] a lawsuit filed by Red Granite Pictures in July sought a declaration that Red Granite owes no contractual obligation to Dumb and Dumber producers Steve Stabler and Brad Krevoy and that the duo are not entitled to any producer fees or credits they claim they're contractually owed on the sequel.

The announcement of the settlement listed the plaintiffs as executive producers, and all claims against Red Granite, Riza Aziz and Joey McFarland of racketeering were withdrawn.

The plaintiffs said in a statement: "We apologize for naming Riza Aziz and Joey McFarland as individual defendants rather than just Red Granite".

It opened number one in Brazil, Slovenia, Norway, Lebanon, South Africa, Iceland, Croatia, UAE, Uruguay.

The general consensus states, "Dumb and Dumber To does have its moments, but not enough of them—and the Farrelly brothers' brand of humor is nowhere near as refreshingly transgressive as it once seemed".

J. R. Jones of the Chicago Reader gave the film a positive review: "Seeing the two fiftysomething stars in their idiot haircuts again is a little disconcerting, like watching your favorite old band on a desperate reunion tour, but this sequel to Dumb & Dumber maintains a respectable laugh quotient".

[81] Andrew Barker of Variety gave the film a negative review, noting: "Sporadically funny and mostly tedious, this 18-years-too-late sequel nonetheless exhibits a puerile purity of purpose".

[82] Joe Neumaier of New York Daily News gave the film zero out of five stars: "From junky production values to the parade of unfunny supporting characters to its lazy energy, Dumb and Dumber To falls on its face".

David Ehrlich of Time Out New York gave the film three out of five stars: "Dumb and Dumber To may not be quite as funny as the first one, but it's the funniest thing the Farrellys have made since".

Club, gave the film D+ and wrote: "A sequel as desperate, in its own "official" way, as the knockoff-brand origin story that previously besmirched the franchise name".

[88] Critic Mick LaSalle of San Francisco Chronicle scored the film one out of four stars, asking: "Is this worse for Jim Carrey or Jeff Daniels?

[89] Manohla Dargis of The New York Times wrote that "the Farrellys are still not much interested in film as a visual medium, and when Lloyd and Harry aren't smacking each other or dropping their pants, you might as well be listening to a radio play".

[90] The Boston Globe's critic Ty Burr gave the film two-and-a-half stars out of four: "Everyone has piled into this dumber, sillier, more consistently funny reprise with an enthusiasm that's infectious, and not in a low-grade medical way".

[92] Betsy Sharkey of the Los Angeles Times wrote: "What felt fresh in Peter and Bobby Farrelly's original Dumb and Dumber, with the Carrey-Daniels dense duo channeling the Stooges and Jerry Lewis and something else entirely, feels strangely old-fashioned two decades later".

[95] The Star-Ledger's Stephen Whitty gave the film one and a half out of four stars: "The majority of it isn't just dumb and dumber, or even crude and cruder.

[97] Wesley Morris of Grantland observed that "the directors Bobby and Peter Farrelly cram the movie with puns and those kinds of sight gags.

But far more often, the comedy's just spiteful, sour or sloppily executed—or, in the case of a running joke about the hideous middle-agedness of Kathleen Turner's character, the mother of Harry's daughter, all three at once.

[100]Mark Kermode, writing in The Observer, "counted a mere three chuckles (one of which I'm fairly sure was unintentional), leaving this several smiles shy of even the widely panned 2003 prequel Dumb and Dumberer: When Harry Met Lloyd".

[101] The Guardian's Peter Bradshaw found "the movie does deliver some laughs, and the climactic scene in which the two low-IQ boys succeed in infiltrating the equivalent of a TED talk is enjoyably bizarre", but concluded: "It's a rental, rather than a visit to the cinema".