About two years ago I was running my first Pathfinder game. The party was around 6-7th level I think. They split up while assaulting a wizards sanctuary. Anyway, they were strong for their level with super high attributes and two to three times their wealth in magic items. One or two people had weapons worth what the entire party should be carrying by raw.
Anyway, three of them split off and went to handle some minions. The principal chantry house guard was a huge air elemental, I think, the CR 9 variation. Now, the party of six, often without the whole group, had killed much more powerful monsters. They were a party of strikers for the most part with huge first round damage.
This air elemental beat the absolute tar out of the three that went after it. The beating was so bad, the ranger was forced to irritate it and get it to follow her away from the rest of the battle. Her whole job became to keep it busy and they never did kill it.
Looking at its stats, it is pretty strong for its CR with flight and a mad reach. Its only weakness is its crappy will save, but none of the six had ANYTHING that targeted will. If they had, they would have knocked it out or scared it off and walked past. They didn't, and so they were forced to take the damage.
When the party confronts a natural weakness like that and they get pounded, do you up the CR of the encounter or do you just laugh at them?
