Sonny Wortzik (Al Pacino) and Salvatore "Sal" Naturale (John Cazale) along with their friend Stevie (Gary Springer) decide to rob a bank. But with no idea of what they are doing it is one calamity after another as first Steve bails on them, then they discover that they are too late as the bank has already had its daily pick up and most of the money is gone. With no money to take they decide to take the travellers cheques but when they try to burn the bank's register so they can't be traced it causes smoke to billow out of an air vent alerting a nearby shop and before they know it the place is surrounded by police. Now these two novice criminals find them selves in a hostage situation with no idea what they are doing.
I hate pretentious nonsense and unfortunately over the years I have read plenty of pretentious things which have been written about "Dog Day Afternoon". Now I am not saying any of those things are wrong but when it comes to your average Joe on the street who wants to know whether or not they will be entertained if they watch "Dog Day Afternoon" then hearing how symbolic of an era and the attitude of a nation it is isn't telling them anything. So to put it simply "Dog Day Afternoon" will entertain, it is a drama which will make you laugh whilst also realise that once upon a time Al Pacino was an exciting actor rather than one who became known for shouting in movies.
So if you don't know "Dog Day Afternoon" is based on a true story and the way the movie tells it is that we have two friends, the third one bottles it, who try to rob a bank but with no real planning other than what they have seen in films end up making a botched job of it. So we see how when Sonny tries to be all bank robbery by having a rifle in a flower box except the box doesn't drop away like in the movies, they set fire to a bank ledger without thinking about the smoke and a strong woman mocks them for not thinking it through. It means that you are constantly smiling at the haphazard ways of these bank robbers rather than laughing at jokes.
But you are also smiling because this is Al Pacino acting, delivering a very specific character with various quirks and he does so in a controlled but entertaining manner. There is shouting as you expect from Pacino but unlike these days it is all part of the character and what a fascinating, conflicted character Sonny is as is Sal in a very different way with John Cazale delivering one of his most memorable performances and making the quiet man as interesting as Pacino's vocal Sonny.
All of the above makes for a thoroughly entertaining movie with Charles Durning also delivering a fantastic performance as the cop who turns host negotiator. In fact I can't think of there being anything really wrong with "Dog Day Afternoon" as it draws you into this situation where the cops are just as ill prepared as Sonny and Sal as they come across as not only gung ho but out there in ridiculous numbers.
What this all boils down to is that "Dog Day Afternoon" is a fantastically entertaining movie which works even for those who like me don't need to know the pretentious sub context side of things which seems to fascinate many who have reviewed the movie.