The central conflict in this novel by Steinbeck is the internal conflict experienced by Ethan Allen Hawley, the protagonist of this novel, as he seeks to be successful in a world where seemingly the only way of gaining that success is to engage in illegal acts. As Ethan begins his working day by addressing the shelves of canned goods, the text reflects on how there is a massive gap between his life now and the promise that his life held as a Harvard graduate and a veteran of World War II. There is significant pressure placed on Ethan to "succeed" and to reach a position where he is secure financially, and the various events in the novel: the prediction of Ethan's future by Margie, his discussion with his friend Joe about how to rob a bank, and the rather callous advice given to him by Marullo, all serve to heighten this internal conflict. Note the following description of how this conflict works on Ethan:
When a condition or a problem becomes too great, humans have the protection of not thinking about it. But it goes inward and minces up with a lot of other things already there and what comes out is discontent and uneasiness, guilt and a compulsion to get something--anything--before it is all gone.
The reference to the title of this novel is of course a direct quote to Richard III, which also foreshadows the way that Ethan adopts underhand methods and deceit in order to get what he wants, exchanging his relative comfort and happiness of family life for riches, power and prestige, but also a broken marriage and family. It is the discontent that Ethan feels that drives his internal conflict and causes him to change his situation.