The ratio of deadly things encountered to dead characters
Once I heard that the reason main characters don’t die when they face so much danger is something along the lines of “If you send ten thousand people into the deadly mountains to survive, most of them will die off. The few that do survive will come back with a lot of stories about how they narrowly escaped death. Fiction tells about the survivors.”
Okay. That works. But if the mountains are that deadly, then the few who do survive are likely to have all of their friends killed off. Maybe the main character is a survivor, but all of their buddies shouldn’t be survivors as well. If the hidden cliff trips up one of every five people who pass it normally, then one of your main five characters should fall off of it. True fact: hidden cliffs don’t specifically target people who don’t have names.
Something can’t really be classed as deadly if it doesn’t kill anybody. Characters without names don’t count as people, either. Making an offhand remark about how the monster “destroyed an entire village” and then having all of your heroes defeat it unscathed just doesn’t work. We don’t know those villagers. The monster seems harmless because all the people we know are unharmed.
If you’re going to play the “this is a deadly scenario where somebody could get killed” card, don’t make it a bluff. Sure, there’s a chance they might all survive that situation once, but if you keep putting them in dangerous places without having any of them succumbing to danger, it loses its effect.
The follower of the day is ivonabarkovic. Her blog contains some of her writing, if you’re interested in reading it.