Sometimes there's a character who just does everything wrong, and then some. When they're being chased by a cold-blooded murderer, they're more likely to run into his arms and whimper for mercy than, let's say, run away. When a flood/avalanche/rock slide/truck comes towards them, they're more likely to stand there gawking than run. When a villain has kidnapped them and has them dangling over a pit of acid, they're likely to taunt the villain and piss him off (and probably reveal that the hero is coming as well) to the point where he decides to kill them anyway, rather than staying quiet, content with the knowledge the hero is coming.