Just some of my thoughts/clarficiations heather -
A 'good sized group' getting killed by one level 9 monster (yes, it only has a CR of 9)seems like it either got extremely lucky or perhaps there was insufficient planning or comminication by the party before/during/after their initial encounter with it. Regardless though of whether the PCs got their butts handed to them by a mean-looking Dragon or a demon disguised as a cute little goblin; sometimes when the going gets rough you may just need to yell 'retreat', possibly summon a disposable creature to hold off the bad guy or drink a potion of invisibility, and make like Monty Python and 'RUN AWAY, RUN AWAY". ;)
Also, permadeath is no more so any character that does run out of free respawns can still come back if they truly 'die'.
Random stats and abilities are a way to continually provide some variety to the encounters, and they will remain. Maybe that goblin had some divine blessing, special ability, or whatever else that makes him different from all the rest. Skill bonuses can be raised or lowered as well, however in the case of rats it's simply their standard skills from the toolset - since low-level creatures don't get random bonuses at all. So if they're spotting you it's either luck or else your PC might need a few more points in hide/move silently.
Gith -
Some good points. It's likely the DC for groups may increase somewhat (however groups also spawn more enemies so this would need to be taken into account as well). I am also considering some form of 'battle fatigue' in which many monsters killed in X amount of time (or some other variable) could result in some decrease to...something. If you or anyone else has ideas on battle fatigue, let's take it offline and sned me a PM with your ideas.
A 'good sized group' getting killed by one level 9 monster (yes, it only has a CR of 9)seems like it either got extremely lucky or perhaps there was insufficient planning or comminication by the party before/during/after their initial encounter with it. Regardless though of whether the PCs got their butts handed to them by a mean-looking Dragon or a demon disguised as a cute little goblin; sometimes when the going gets rough you may just need to yell 'retreat', possibly summon a disposable creature to hold off the bad guy or drink a potion of invisibility, and make like Monty Python and 'RUN AWAY, RUN AWAY". ;)
Also, permadeath is no more so any character that does run out of free respawns can still come back if they truly 'die'.
Random stats and abilities are a way to continually provide some variety to the encounters, and they will remain. Maybe that goblin had some divine blessing, special ability, or whatever else that makes him different from all the rest. Skill bonuses can be raised or lowered as well, however in the case of rats it's simply their standard skills from the toolset - since low-level creatures don't get random bonuses at all. So if they're spotting you it's either luck or else your PC might need a few more points in hide/move silently.
Gith -
Some good points. It's likely the DC for groups may increase somewhat (however groups also spawn more enemies so this would need to be taken into account as well). I am also considering some form of 'battle fatigue' in which many monsters killed in X amount of time (or some other variable) could result in some decrease to...something. If you or anyone else has ideas on battle fatigue, let's take it offline and sned me a PM with your ideas.