Elder-Basilisk said:
1. Don't get into fights. Intimidate, cower, whatever, but don't fight because you're obviously too good to be what you appear to be.
2. If you do get into fights, leave no survivors. Dead men tell no tales--at least if you ensure that speak with dead won't work.
The mercenaries are being employed to deal with rampant lawlessness, will travel in groups commanded by a lawful knight (magi are 'knights' too in the campaign) and will see combat.
There seems to be 2 camps rejecting my houserule (or RAW as Karinsdad put it).
1) It is physically impossible to volunteerily lower values gained through experience.
2) It is possible to hide great skill via the bluff skill.
#1 is clearcut in that it disallows any possibility of success. #2 implies that only rogues & bards can hide their fighting prowess well & that clerics, rogues, bards & paladins are best to detect such skill.
My response to #1 is outright rejection on the grounds that it depowers high level characters from tactical choice that they have earned and deserve. The RAW give tacit support for this approach by extrapolating from a similar rule, & other than the fear of devaluing the bluff skill, there is no combat advantage to be gained.
#2 is far more tricky for many reasons:
* Is a bluff check necessary?
My houserule is that while they may deceive onlookers it is because they actually have the reduced skill within their upper limit. If the 14th level knight gets surprised with a power word, he functions at his current max hps.
* Does this depower the bluff skill?
The #1 camp would say no because +100 in bluff doesn't allow the actual reduction in base stats. Ok, that aside I actually do see a place for sense motive; given decent observation over a period of time a comrade/onlooker should be able to have a chance to detect something is amiss. On a similar note, if the sense motive succeeds the onlooker could ask a straight question and force a confession or a bluff check.
* Should a bluff check use opposed or a static DC roll?
It strikes me as wrong that the most skilled fighter is one of the least able to control their apparent skill while a 3/4 type is the most able; again I have to reject the bluff check but if a check had to be done I'd make it a static DC - DC 0.