Conflict is an essential element of any story, adding drama, developing characters and creating connections between the reader and the story. In The Wizard of Oz, Dorothy must face internal conflicts as she recognizes that "there's no place like home" and she must battle the witch and various external forces beyond her scope. When evil is confronted with good, the outcome can only be good as Dorothy is "protected by the Power of Good," which even the evil winged monkeys recognize. The irony of the deception of the wizard, a truly "bad" wizard but not a wholly "bad" person ensures that Dorothy can forgive his shortcomings. These conflicts ensure that the story and the characters can develop and especially Dorothy. She and the other main characters, the Tinman, the Scarecrow and the Lion all discover that they have strengths they never realized and "powers" to change from within. Emotional connections are brought about by the external conflicts which must be faced.
The Wizard of Oz therefore has numerous conflicts, both internal and, seemingly external. It is the fact that Dorothy killed the Wicked Witch of the North, even accidentally, that allows her to improve the lives of others - the Munchkins- but it is her shoes that provide the key. Dorothy just needs to recognize it. Primarily then, it is Dorothy's internal struggles that create the main conflict and ultimately Dorothy will be able to find her way home by her own means, clicking her heels together, revealing the conflict between man and self.