Death=Real Death
A rule in writing that says that if something happens to a character that would kill them in real life, they die. exceptions are present, such as if they have healing powers or something happens to resurrect or save them legitimately. usually, this rule is abandoned in favor of a much more fan-pleasing rule, "if you didn't see the body, they are not dead. "
"wait, did that guy really die? he only fell off the roof."
"Death=Real Death, dude. sorry"
"Death=Real Death, dude. sorry"