Rashomon: Whose Story Do You Trust?
The term "rashomon" comes from a Japanese film of the same name by the legendary Akira Kurosawa. In it, four people give different accounts of two heinous crimes from their own different perspectives. It has been used or parodied by everyone from CSI to Codename: Kids Next Door. Each person's account of events is one piece of the puzzle, but how do you know whose story to believe? Whether you are a fan of this genre or are planning to write one yourself, here are a few hints on how to pick out the one person whose story is more accurate than the others.
The Only Sane Man. According to tvtropes.org, there is usually one person out of an entire group that is steadfast in their logic or attitude towards things, and that is usually the person whose story is more credible. Take for example the rashomon-themed episode of Invader ZIM. Out of all four people in the group, Gaz is the most reliable so it's her story that's the closest to the truth. The rest of them are varying levels of insane (or other non-trustworthy traits). Beware of otherwise sane people who lie to make themselves look better (ZIM and Dib are both guilty of this). It is also worth noting that a lie does in fact normally contain a part of the truth (though forced to lie and incredibly insane to boot, GIR does truthfully say that Dib is consistently mean to ZIM).
Simplest is Best. Gaz's story is also the shortest, whereas the boys' embellishments drag out the story longer than the recorded footage they were brought in to discuss. While the other three make up stories that range from blatant lies to delusions of grandeur, Gaz's story is simple: Dib dragged her out with him into the woods, where they found ZIM and GIR without their disguises on, and then she kicked Dib in the back of the knee, forcing him to fall over and drop the camera - end of story (though the re-enactment actors do take her description of Dib and ZIM as "stupid" a little too far). The devil is in the details, so the simplest explanation is usually the most reliable unless the situation is reversed and the liar is simplifying to obfuscate important facts. If characters are going to lie, they had better be in a state of mind that allows them to remember the lie and tell it without changing a thing. However, that's not to say that certain states of mind don't cause non-liars to get certain details confused.
Middle-of-the-road. Some say the truth is somewhere between what one person says and what the other person says, or sometimes the average of what a large group of people say. This is best left up to a team of investigators, as in CSI, especially when a crime has been committed. Other times it may not matter, such as the KND's report to their superior officer about how they managed to botch picking up a pizza for her (no matter what any of them says, she is not pleased and in the end doesn't care whose fault it was because she is tired of listening to each of their stylized tales). That's another matter to consider as well - each person will have their own biases based on their perception of events as well as how they choose to tell it. It could either be a conscious decision (what they consider important to the story) or an unconscious one (their subconscious worldview).
In conclusion, the possibilities are endless. The more characters you have involved in a story, the more potential you have for them to distort reality and add twists to your overall tale of mystery and intrigue (or simply spice up an otherwise mundane story that no one is impressed by in the slightest).