Fauchard1520
Adventurer
A couple of different sources have shaped my thinking on this point. The first is "gygaxian naturalism."The World Isn't Fair. Kinda falls in line with the above (maybe your Eldritch blast won't win the day) and I run my worlds gritty with the idea that a diverse group with diverse skills willing to think outside the box have better chances of conquering things that don't seem fair.
Gygaxian "Naturalism"
I refer, from time to time, to a concept called "Gygaxian Naturalism." I realize that I've never actually explained what I mean by this phra...
The other comes from the Alexandrian's take on the CR system. I'm looking at the CR 10 roper example specifically:

Revisiting Encounter Design
One of the first reviews I ever received for a book I had written was for the mini-adventure The Dragon's Wish, which was published by Fantasy Flight Games during the early D20 boom. The reviewer hate