Man Of Few Posts said:
The main intention of these long term injuries to recreate the feeling of the PCs coming out fight with a dragon, knowing that the fight took something out of you that can't be cured just a night's rest.
If this is the goal, I would suggest going with limiting the healing surges available, and reducing the amount of healing a rest provides based on that...
what I mean is something like:
Your max number of healing surges per day is reduced by one for each critical hit you sustain. If you are reduced to below 0 hit points, the number is reduced by two. This does not affect the number of healing surges you have to use in that day.
When you rest, you regain a number of hit points based your max number healing surges.
- 1 surge, regain 1/4 hit points
- 2 surges, regain 1/2 hit points
- 3 surges, regain 3/4 hit points
- 4 or more, regain full hit points.
At the end of your rest your max healing surges increases by 1 if you still have a reduced amount. You regain only that many healing surges to face the new day with.
Example: Joe Fighter has 5 healing surges. In a fight he takes two critical hits and gets knocked to 0 hit points, reducing him to a max 1 healing surge. During combat he can still use the 5 healing surges he started the day with.
That evening the group rests. Since his max is 1, he wakes up from the rest with 1/4 hit points and his max healing surges improves to 2.
Avoiding combat, the next evening the group rests. His max is 2, so he wakes up with 1/2 hit points and 3 healing surges...
etc..
With this any character that was severly beat up will take a couple days to recover and will tend to avoid heavy combat. You can describe it as physical injury, or morale issues, or simple combat exhaustion.