I’m trying to create a story that they can play and killing them seems counter intuitive. My goal when building encounters is to challenge them and push them to their limits but not murder the entire party.
Doesn’t that sound kind of contradictory (and counter intuitive) itself? I’m challenging you – but the final arbiter of whether you failed the challenge- ie, death, is completely off the books!
It’s like me giving you a really, really hard maths quiz that tests your maths limits – but no matter how many you get wrong, you always pass the quiz/you always live.
I’ve actually heard quite a few actual play accounts where players have tried to do things that would get their PC killed, to see if they could die. Ie, fail as many/all questions, to see if it’s actually possible to fail the quiz.
I think it’s classic illusionism, where even the GM has himself under an illusion – where he doesn’t really look at what he says to himself “Hey, what I just said just freaking contradicts itself!! What the hell was I thinking?”. Instead he thinks he can push them to their limit, but never actually kill them. It’s like the impossible thing before breakfast, where two mutually contradictory things are asserted as happening in the one game.