The love triangle may be one of the most abused elements of contemporary fiction (particularly in the YA genre), but that’s for a good reason. The reason is this: good things come in threes. Beginning, middle, end; the Three Musketeers; birth, life, death; Ego, Superego, Id; past, present, future. It’s natural to structure elements in 3s, but there’s also a compelling mathematical logic for having three primary characters* in your novel.
Killing a character isn’t as simple as it seems. From readers not caring about a dead character to awkward deaths that contribute nothing to the plot, it’s easy (as with everything in writing) to screw up. What’s more, there’s no one right way to kill a character. There are, however, some story elements that are more or less universally effective when it comes to literary homicide:
1. Make readers care
Making readers care is a writer’s toughest, but most important, job. If readers are emotionally invested in characters, their deaths (the characters’ not the readers!) will matter. The death of an interesting, three-dimensional and compelling character will hurt far more than an undeveloped character’s demise.