On villains
Most stories have a villain of some sort to generate conflict (also known as an antagonist). Beginning writers are advised to give their hero or heroine (protagonist) a goal, and to have an antagonist who works against the protagonist, preventing him or her from reaching their goal. The tension rises as the protagonist struggles to achieve the goal and is knocked back more and more decisively; eventually a point of despair is reached, then a solution is envisaged and there is a final confrontation, during which the antagonist is defeated.