I'm sure this idea has already been visited by many, but just to create a current discussion, i ask:
how would you feel about a game mode (that could be turned on and off) that would give the player a hunger, thirst, and sleep level that the player would have to maintain? (Much like in New Vegas). And an accompanying Survivor skill that would make the player more efficient at using cooking pots, gaining sleep bonuses, and maintaining thirst and hunger levels?
I feel that this would not be to hard to incorporate and would add a whole new depth to the game.
Some ideas for perks could be additional food harvested from animals, more health and stamina gained from self cooked meals, the ability to set up mobile fires and cooking pots, mobile sleeping bags, and mobile tents (for additional sleep bonus).
Any other ideas?