Exactly what it says on the tin.

This is a movie about two guys.  Ones name is Harry.  He is dumb.  Lloyd is the other and he's dumber.  Put them together and you have Dumb and Dumber.  Two guys who fall under the category of "Too dumb to live" yet somehow they do live.

Harry and Lloyd are clueless losers who share a crummy apartment in Rhode Island who drift from one job to another since either one of them have just enough brain cells to keep from being in an animal cage throwing poo at each other.  They're dream job?  Open a worm farm store.  Like an ant farm but with worms.  Lloyd while working as a chauffeur gets a job to drive a beautiful socialite named Mary and takes her to the airport.  When he sees that she leaves a briefcase behind he scrambles to give it back to her but he's too late. 

Going home and meeting Harry who lost his job decide that at least taking the case to Mary would be a good deed and maybe be good for the both of them, not to mention that Lloyd has fallen in love with Mary.  So off they go across the country in the greatest vehicle ever on wheels, The Shagg'in Wagon to meet Mary in Aspen unaware that Mary's case is full of ransom money and the two kipnappers who were expecting the money are now following Harry and Lloyd.  Dead pets, wrong turns, hot peppers and more ensue between Rhode Island and Colarado.

This was made back in a time when jokes were in movies, physical and spoken jokes.  We didn't have walk ons and cameos, endless references to our other works or just other things in general.  The one thing I hate in a lot of comedies is when they start with the in jokes to replace real ones.  References aren't as bad but again aren't funny and it takes time away from making things that could be funny.  In this movie, you have pratfalls, jokes about laxatives, stupid sight gags, and more.  This movie may live up to it's name but it's funny and it's full of real jokes.

This movie is one of the "Big Three" that Jim Carey made in 93 and 94 among his earliest and biggest hits and it's also the first major movie by the Farrely Brothers who along with this movie helped usher in more of the "dumb, gross and stupid" comedy movement at the time.  What stunk about the movie is that it had a great pairing of Jim Carey with Jeff Daniels and they have not worked together again.

Dumb and Dumber was a bit of a trend setter since we got Billy Madison and similar movies of it's ilk later down the line.  A second movie came out later in 2003 but it was Carey and Daniels less and it was also a prequel.  Dumb indeed.