dcollins said:
Let me ask this: Do you agree that a stone giant is about as powerful as a 12th-level NPC Fighter? Do you think they should have the same CR? If so, what would it be?
No, it´s not, but it deserves a more detailed answer.
Suppose we clone a 7th-level party and make them fight. By definition, that´s a very difficult fight, with a 50% chance of either party winning and most likely, it´ll end with a lot of dead people in the two sides (if they fight to the death). Thus is a EL 11 encounter. Since they are four, that means that only one of them
should be CR 7.
Let´s look at the giant, supposing a CR 7 giant (a hill giant, IIRC). It´s supposed that a party should spend 1/4 of their resources fighting him: spells and potions, hit points, etc. We agree that this is not always true, but at least is how the CR and EL system is designed.
Is the CR 7 hill giant equal to the party´s figher CR 7 in a pit fighting, gladiatorial match? No, most of the time the giant will beat the fighter into the proverbial bloody pulp. I´ll add, to make the paradox bigger, that I think that a 7th level party would find easier to beat 4 hill giants than clones of themselves.
What happens then? The picture is bigger than the actual numbers in the character´s sheets; the party´s combined, if played properly, weight more than the giant´s combined brute force.
That conclusion is, obviously, that the CR and EL system is not perfect. Fighters and other classed characters are only worth their CR when supported by other classed characters. Groups of monsters entirely built around a single strong point (and with obvious weak sides) are easier to fight against than the combined EL would suggest.
However, I´m reasonably happy with the system: Improving it´s accuracy would make it harder to use, and the failures are easy to correct once you know where does it fail.