The Morality-Mortality Equation

The Karmic Equation of Evil Actions, Consequences, Morality and Mortality states that:

The Immorality of an action (I) times the Success of the action (S) equals the mortality of someone close to the evildoer (M). Or I*S=M.

Therefore, the Immorality (negative karma) of the action equals the Mortality (likelihood of death in plot) of those close to the evildoer.

This is sometimes called "Karma by Proxy" because if Bob, the main character, does something bad, he, by virtue of being the main character, is less likely to die than Alice, the person Bob cares about, because of the way the forces of Karma and Plot interact. Other factors are the allure of that shiny Newbery Medal, and the Rule of Drama.

For example, if the story is Bob's Start of Darkness, Bob can't die, because that would derail the Plot. Bob is Doomed by Canon to survive. Therefore, Bob's Bad Karma rebounds off of his Plot Armor onto Alice, because she is closest to Bob.

And if you have ever wondered why the villain's Mooks are so much more likely to die than him, now you know. A morally good villain will take care of his Mooks, but a successful villain doesn't have to.

Likewise, on the Heroic side of the equation, heroes tend to cast a protective force on their friends and loved ones. This is because The Hero will ALWAYS save their friends in the Sadistic Choice of the "Friend or Idol?" Decision, or in the choice between power and love, or in the choice between his loved ones and just about anything.

However, the equation goes both ways. Sometimes, even the most kind and loving Messiah can get downright scary when those close to them are in danger. Once you've kicked the hero's Morality Pet off a cliff, you can expect the hero to do things that he wouldn't even consider otherwise.

And Now You Know.

Anime and Manga

 * In Code Geass, once Lelouch starts loosening his morals, the people he cares about die (like ), bad things (like  ) start happening, and he loses his best friend (Suzaku).

Comic Books

 * Non lethal positive example: in The Life and Times of Scrooge McDuck, The title character loses his Number One Dime after attempting to steal a sacred opal from a cave. Later in the story, he is rewarded when he returns the opal (as said cave collapses) with the return of his dime.

Film

 * In Star Wars: Revenge of the Sith, Anakin has just killed several children and a Jedi Master. His wife, Padme, refuses to follow him on his path to The Dark Side. He uses The Force to choke her, causing her death. However, due to the force of Plot, she lives long enough to die later from childbirth. This is one case where Karma ricochets back on the evildoer, as Anakin is burned by lava, becoming Darth Vader, which was ordained by the Plot to happen.
 * Darth Vader is a very evil and very successful villain, and as such, it is NOT a good idea to work for him, as he kills his own Mooks when they mess up.

Web Comics

 * In Eight Bit Theater, Black Mage is very powerful, but not very successful, and fails miserably at trying to kill the other light warriors. When he finally does achieve ultimate power and kills the other light warriors, he accidentally kills White Mage, the only thing in the universe he cares about. When the other light warriors and White Mage are resurrected, Black Mage soon loses his ultimate power.
 * In Order of the Stick: Start of Darkness, Redcloak can't die because it's a prequel, so his brother ends up paying for their evilness instead.

Web Original

 * In Dr. Horrible, The title character attempts to kill Captain Hammer in order to get into the League of Evil. In doing this, he indirectly causes the death of ; thus allowing him entry into the League. He wins, but in the worst way possible.

Film

 * In Star Wars Attack of the Clones, Anakin, after having his mother die in his arms, takes out his anger and frustration on the vicious sand people who killed her. He even kills the women and children of the sand people village.