FireLance
Legend
You say that like it's a bad thing.reanjr said:If you have decent players then the typical, expected level of wealth in D&D allows players to take on creatures with CRs well beyond their level.

Certainly, if your players know they are going to fight a white dragon and load up on flaming, dragon bane weapons and potions of cold resistance, the fight with the dragon will be trivial. But it's the preparation, and not just the gear, that makes the difference. Even without appropriate (but still decent) gear, the right tactics and spell selection can make a normally difficult fight into one that is easy.
Anyway, I've read somewhere that CRs are pegged against a party of PCs who have not made optimal choices, so that inexperienced DMs (who may not be able to accurately judge the danger of the creature with respect to the specific mix of PCs he's running the adventure for) are less likely to throw something that will wipe out a party of inexperienced players (who may not make the best decisions for their characters). The philosophy behind this is that it's better to have several easy encounters than a single TPK. So, it's not surprising that the standard rule of thumb of:
CR = party level - standard encounter
CR = PL +2 - difficult encounter
CR = PL +4 - deadly encounter
for sub-optimal characters may become:
CR = PL - easy encounter
CR = PL +2 - standard encounter
CR = PL +4 - difficult encounter
CR = PL +6 - deadly encounter
for experienced players who make good choices for their characters.