Characterization is the art of bringing characters on the page to life of which Mark Twain is truly a master. Characters can be flat, or one-dimensional, round in which the reader knows what truly makes the character tick. Characters can be static, meaning they don't change from the beginning to the end, or dynamic, meaning they transform by the end of the sotry. A character is created through actions, through dialogue, through conflict, and reactions to situations.
Tom Sawyer is a mischevious but loving boy, and one who is fascinated by adventure. When he manipulates a situation, as in the fence painting scene, for his own personal gain, we chastise his actions but secretly root for his success. When he is tormented by his love for Becky wearing his emotions on his sleeve, we root for him even more. When he struggles between right and wrong, we cheer him in the right direction. Tom Sawyer is a round and dynamic character, one with whom the audience can love and despise all at the same time which is truly the magic Twain brings to the reader.