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Hemlock Yes, it's dangerous to generalize, I get that. It's also useful to notice trends and patterns too. And of course I'm interested in other GM's/player's views on the matter, but my initial motive for this was
selfish and not altruistic. I want guidelines that work for
me and my group.
Which, for the record, is comprised of a Fighter/Paladin, a Rogue, a Cleric, a Sorcerer, a Ranger, and a Monk-a-lock (Monk/Warlock).
If you think of the classic D&D party: Fighter, Rogue, Cleric, and Mage (with Ranger being the optional 5th wheel), well then my group's party certain qualifies as "classic." With the exception of the creepy monk-a-lock.
And if we're going to generalize encounter difficulty estimations, then we can't go too wrong with the classic D&D party as our assumed party typology. Sure there are going to be some groups that deviate from this norm, but it's classic for a reason! Personally, of the 4 gaming groups I've been a part of, they've all covered the four basic roles of the classic D&D party in every game/campaign we've played.
I'm avoiding getting that deep into analysis for now because of the great variance in d20 probabilities, player tactics, how GMs run monsters, and so forth. It's a good point though that play style can have a big impact on encounter difficulty. Whether or not that can be quantified in any meaningful way, I don't know.