Most people are familiar with the story of the poor little boy who is born in a Victorian workhouse and sent to an orphanage after his mother dies in childbirth. Ironically, aged nine Oliver is back in the workhouse as he is too old for the orphanage and of an age to be apprenticed. The boys in the workhouse are truly starving and receive very little gruel (porridge) so they draw lots to decide which of them should ask the master for more food. Oliver's famous words are "Please sir, I want some more" (ch 2). After this preposterous request, Oliver is offered up for apprenticeship with the added incentive of a five-pound bonus to whomever will take him. He runs away. This is the legacy of Oliver Twist.
1. The book was written by Charles Dickens and features the very best of his imagination whereas the movie is an adaptation of his original thought and, as such some of the characterizations differ between the book and movie.
2. The book was originally written for publication in a weekly magazine and therefore it has a structure which includes more characters, sub-plots and unexpected possibilities because there would have been a need to appeal to audiences on an ongoing basis. However, the movie follows a more traditional story-line.
3. In the book, the narrator often informs the reader what Oliver is doing or what he is about to do whereas in the movie, Oliver gets to act out this character. This means that the Oliver of the book is not as central a character as he is in the movie which focuses on Oliver and main characters such as The Artful Dodger, Nancy and Fagan and omits or downplays other characters such as Mr Bumble and Mrs Mann.
4. The movie leaves out details of Oliver's past as a "parish child," having been brought up "by hand" (ch 2) and his ceremonious naming by Mr Bumble, the beadle, in terms of an alphabetized system.
5. The book reveals that Fagin is a Jew and is cruel to the boys but in the movie his religion is not mentioned and his cruelty stems from his need to make the boys wise and street-smart and not from neglect and abuse. Bill Sykes is the evil incarnate.
6. The environment within which Oliver finds himself is truly undesirable and in the movie care has been taken to avoid or to be vague concerning some details, such as relating to Nancy and Sykes's dog which realistically and graphically may not be appropriate for children.
The movie has a rating which makes it suitable for children's viewing.
Polanski made several adaptations to streamline the novel to fit a film format. One major change was omitting the role of the evil Monks Leeford, Oliver's older half-brother. Monks's father had a relationship with Agnes, Oliver's mother, who died while giving birth to Oliver. In the novel, Monks has been taught by his own mother to hate Oliver. It is Monks who pays Fagin to turn Oliver into a criminal, which is why Fagin is glad to keep Oliver around. Monks knows that their father's will leaves the bulk of their father's fortune to Oliver—unless Oliver becomes a criminal. Therefore, besides his motivation of hatred, Monks has a strong financial incentive to turn his half-brother toward a life of crime. The movie also leaves out the story of Rose Maylie, Oliver's pure and beautiful aunt.
In the movie, Oliver is simply left as an orphan, with no other explanation of his background. Fagin and Sikes become his enemies, instead of Monks, and try to kill Oliver in order to silence him.
The major difference is that the film leaves out everything in the novel that refers to Oliver's past history.
A second difference is that the film avoids the novel's episodic structure with multiple cliffhangers ( a by-product of its serialised publication) in favour of a more direct, linear progression.
There is useful material on the website of the British Film Institute, below.