This master's thesis will analyse the literary source „Diary of a Wimpy Kid: Rodrick Rules“and its adaptation into an animated film of the same name. Significant differences between these two media have been observed. The book focuses on all the events that Greg Heffley documented during the period when he was writing his diary, without giving particular importance to any specific event. On the other hand, the film focuses around a specific event and the accompanying situations that arise from it. Differences in the sequence of events have been noted, where the beginning, middle, and end in both media are entirely different, and even events mentioned in both media have their variations. Through a detailed analysis of the literary source material “Diary of a Wimpy Kid: Rodrick Rules” in the film format, differences have been highlighted, including the number of characters and how are they characterized. It has also been explored how the film places more emphasis on creating an atmosphere compared to the book, where the environment did not receive the same level of emphasis. Factors contributing to adding depth to the film have been examined, including music, lighting effects, and the use of colour to emphasize situations. Although this film adaptation has introduced some changes in comparison to the author’s vision in the novel, it has retained the key characteristics from the book.