Wilderness Fatigue

This is the relatively simple mechanics I use for when the PCs are sleeping on rounds, or under trees any sleep that is not in a tent. Each morning when they wake they have to take a Survival Check or Fortitude Save (whichever is higher) of DC5  + 1 for each day in a row they haven't slept int a proper bed


Then they get modifiers to their roll based on circumstances and equipment (others of these could be added at whim or depending on exactly that, circumstance)

+2 for bedrolls

+2 for lighting a fire

-2 for the temperature in spring or autumn

-4 in winter

-6 in extreme cold

(note my campaign generally takes place in the far north of the game world so if the PCs were in the southlands, which they are now i would change this table, to only taking penalties in winter at -2, if they are further south i would start to shift the penalties based on humidity and rainfall etc)

+2 for tents

+1 per manservant to make or break camp (this is only for each player - so if one player has one manservant then they get a +1 bonus, if another player has two then that other player gets +2)

+2 for being able to wash and PC specifying that they wash (cause PCs are generally a constipated and smelly bunch)

+2 for winter blankets

-2 for light precipitation (this would count from the days travel not just the overnight stay)

-4 for heavy precipitation (same as above)

Failing the saving throw indicates that PC is at -1 to ALL checks and attacks etc until they the rest an extra hour for each penalty point they have accrued in a common quality or better inn, or twice as long in a poor quality in, or 4 times as long in the wilds (-1 penalty restored from 9 hours rest in a decent inn,  10 hours rest in a poor inn, 12 hours rest in the wilds).

I haven't needed to adjudicate this for a long wilderness expedition yet, but if the party were to go wilderness adventuring until the point at which characters are at risk of getting into the -10s on their checks I would probably rule that if a character takes more than their constitution score that they suffer fatigue as per the 3.5 rulebook (something along the lines of not being able to run, forced march or charge). 

After that every additional point a character takes I would impose 1 point of damage in addition to another penalty point and I would start forcing spellcraft checks to determine whether or not casters can prepare spells (DC10+spell level with a -1 for each damage past there con score) though I kind of want to make that a rule for any roughing it, but we'll see.