Adultery. Treason. Sacrilege. Fratricide. There’s a form of betrayal for every occasion. Villains can betray villains who can betray heroes who can betray heroes or villains in turn. Individuals can betray other individuals who can betray groups who can betray other groups or individuals themselves. Hell, half of all science fiction is about the betrayal of man by machine, or man by man for machine—or sometimes even machine by man.
Betrayals are by definition horrifying and fascinating, even in fiction, because you cannot have betrayal without first having trust. Without first developing a meaningful relationship between the characters you intend to have betray each other, your clever plot twist is just common cruelty.
So to write a meaningful betrayal, you must first develop a strong relationship between characters people care about. Then, you must select the right flaw to bring it all crashing down. There are a number of good, solid flaws to choose from. Here are a few of my favorites:
- Temptation, particularly for power. The classic, most biblical of betrayals. Boromir betrays the fellowship out of temptation in The Lord of the Rings, Edmond betrays his siblings for Turkish delight in The Chronicles of Narnia—and in both cases this selfishness is seen as the primary downfall of man. Characters who betray out of temptation can be good men who feel the ends justify the means, weak characters who feel the present so much more strongly than the future, or simply characters so wounded that no matter what is offered to them, it will never satisfy their desires.