Writers bring stories to life through characters, and understanding the different ways characters can be built is essential. In terms of dimension, a flat character is one-dimensional with few traits, often serving a single purpose, while a round character is complex and multi-faceted, capable of behaving in surprising yet believable ways. In terms of change, a static character remains essentially unchanged over the course of the narrative, while a dynamic character undergoes significant internal transformation. That internal journey is called a character arc, and it typically moves a protagonist from a flaw or false belief toward growth or truth.
Arcs come in recognizable shapes. In a positive character arc, the character begins with a flaw or false belief that they gradually overcome, ending the story in a better state; Ebenezer Scrooge is the classic example. A negative arc depicts deterioration, as the protagonist succumbs to a flaw or embraces a false belief, as Walter White does across Breaking Bad. A flat arc, despite the confusing name, describes a character who already holds a core truth and does not change internally, instead changing the world or characters around them; Captain America is often cited as a clear illustration. Beyond these individuals, stories draw on archetypes, the universally recognized types such as the Hero, the Trickster, and the Shadow, and use foils, characters whose contrasting qualities highlight specific traits of the protagonist, as Draco Malfoy serves as a foil to Harry Potter.
Behind every compelling character stands an equally compelling antagonist. Strong antagonists have clear motivations, believe themselves justified, pose a credible threat, and often mirror or challenge the protagonist's values. Conflict, the engine of the story, comes in several recognized forms: character versus character, character versus self, character versus society, and character versus nature, with some traditions adding character versus technology or character versus fate. Internal conflict, the struggle within a character's mind between competing desires, fears, or moral dilemmas, can be just as gripping as any external battle. Backstory, the history a character brings into the story, should be revealed in small, relevant doses through dialogue, flashbacks, or brief narration rather than in large blocks that interrupt the flow. Without conflict, after all, there is no story at all, because it is conflict that drives the plot, reveals character, and gives readers a reason to keep turning pages.