After reading SneeR's excellent theory thread
with it's accompanied replies I fell enamored with the idea and wanted to come up with something of that sort. Unfortunately, I was prompted that the thread is old and to reply only if I'm absolutely sure. Hence the new thread.
I came to something close which I wanted to run by you all and hear your different opinions.
The basis is that each ability has a few stages a la StarWars saga condition meter.
There is one positive stage to represent temporary boons.
Three negative stages that are steps. First one is a minor case (-2), usually no special disadvantage. Secondary is slightly bigger negative (-4 or -5), maybe special ruling e.g. can't use full round action when Exhausted (-5 at constitution). After this, major penalty which makes the character nigh impossible to take action at certain aspects, like Paralyzed (-10) at dexterity. This would place more importance at working together and avoiding or helping inflicted teammates.
The last one is essentially "death" state. If you've been inflicted 4 times at the same ability then you're out. Attempting to mimic the Gradual Defense in SneeR's post.
Here are the conditions from the 3.5 edition arranged as described above. At this point I'm not sure whether it is relevant to keep the conditions as they are or change it to something new.
One thing that is missing is the Hp row.
I think that it is possible to implement something similar for it, incorporating the 3 Death save rolls into the 4 condition steps and also creating new conditions, such as Bleeding, Wounded, Maimed and bloodied (from 4th edition). One thing different is that while the ability saves requires you to attack higher then the saves themselves (vs. ability score), the hp is a pool that usually drains away - you chip away at it until you reach zero and fell your foe. Can it exist within the condition meter? Does it needs to change? Not sure.
Your input greatly appreciated.