CapnZapp
Legend
Very much this.This is just one of the myriad of things that makes me wonder why WotC even bothers with challenge ratings, encounter building tables and the like. It seems like so many players take them as gospel, follow them to the letter, then get annoyed when they don't work right for their particular group. That group of 20 Bandits against 4 melee PCs makes the battle difficult enough that the XP that they get out of it (due to XP multipliers for large groups) doesn't seem nearly enough... whereas the same 20 Bandit group against 4 PCs that can drop a pair of AoE spells in the middle of them at the top of the battle seems like a cakewalk.
If WotC had just left "encounter building" and "challenge ratings" out of it and just told DMs "figure out what your group can handle and create fights to challenge them"... DMs would build towards their specific party and not just using arbitrary numbers and wonder why they don't work right. It's how DMs always had to do it way back when and we got pretty good at just eyeballing things based on monster stats and XP gained... and it's a skill that too many DMs these days have never really learned how to do.
I'd encourage all DMs to occasionally just put together a random encounter using nothing more than your instincts on what you think your group could handle-- not bothering with any encounter building equations or ratings or anything-- and just see what happens.
Sadly, I believe challenge ratings sells the game. Gives encounter building a pseudo scientific sheen. In effect, it tells newbie DMs "you can do it. Just follow these steps and you will have an average, difficult or deadly encounter, every time"
It's all a lie, of course.
I weep at the thousands of hours being wasted on meticulously calculating ECLs or XP budgets or whatnot. Not to mention the countless arguments in forum threads just like this one.