Actually, one other mechanic has made the campsite more real in the game, the three watches and the chance of attack. But this is just the wilderness impinging on the campsite. And with how abstract wilderness travel in the game tends to be, camp turns out to be just another set of encounter rolls; a single choice about who will be up when the attack in the night comes.
I want campsites to be more than that. To me they are the extension of the hearth into the wilderness and only if they feel that way, a bit safe, a bit like what we've left behind, will attacks in the night be jarring. But even if we decide to never roll for attacks in the night again, I think the comfort of camp can be a contrast that helps bring out the work and danger of traveling through the mountains and swamps, and dark forests. And really, down into the mythic underworld.
Around the campfire is where characters share what they've heard of the dread place they're traveling to and what they miss about home. But for this to happen in our shared, imagined world, I think we have to provide some mechanics that try to make it feel like a campfire and hopefully give players a few interesting choices as well.
So what mechanics? As usual, I'm aiming for brutal simplicity; the least bookkeeping and calculating possible that still gets the job done. Here are a few houserules that might make a campsite feel more real in an adventure game:
Food & Drink
Most characters have rations, or hardtack, or trailbread. Cooking fresh food would make a fire important and camping for the night more of an event. I say +1 hp per level per night in camp when you are eating freshly prepared food. This really works if you have a simple hunting and gathering system. Which in turns makes different landscapes feel more tangible because they have more or less game available. (I'm still hammering out the kinks in my own. See here for it's origins ) But, even without hunting it means stopping in villages and buying or raiding for livestock becomes a reality. On long expeditions players may even want to take livestock with them.
Music in the wilderness means you are not afraid of being attacked and what reminds characters of home more than the songs of home. +1hp per level per night in camp where music is played. The idea came for having bards as hirelings, but I've allowed characters to buy and play their own instrument. This costs some money and takes up encumbrance space. And how about the noise? I wouldn't want to penalize too much, or players would never play music in camp, maybe just a +1 to encounter rolls.
If you have a system of wear and tear for armor and weapons, camp becomes a place to hone and oil blades, tighten grips, and polish armor. See this post for Brendan's simple equipment deterioration system and here for how I would tie it to the campsite.
I think one aspect of campfires that makes them what they are is the stories told around them. One approximation of stories could be rumors. We could use camp as an opportunity to introduce rumors from hirelings "My gran all used to say . . .?" But I also like the idea of giving players a chance to make up stories of their own. The problem is some players will be more comfortable doing so than others, but as long as one person can manage a goofy or spooky tale maybe it would be fun enough to implement. How about story responsibility rotates through the players, one each camp night (it is an abstraction meant to stand in for lots of talk) and if the player pulls off one then everyone will receive a +2 to saves made in the location the story was told about. So, for multi-day travels through the wilderness it might not be a big loss to skip the story, but the night before reaching the dungeon or the dread location, it would be worth an effort to come up with something. Rotating through the players allows shy or reluctant players time to think up something or get suggestions from other players.
If the campfire is the extension of the hearth, maybe it should offer some protection against the dark. I'll repost an idea here:
A cleric, or anyone versed in the Old Ways, can take a stone weighing a half-stone or more from the night's fire. By incorporating it into the next night's fire ring they make that fire a hearth. Each night of doing so makes the hearth magic stronger. Undead and shape changers can not enter the light of a true hearth.Half-stone is ~7 pounds which is one of my simple encumbrance slots. I'm not interested in the bookkeeping part now. Maybe just, using the hearth a second time on gives the protection, but skipping a use in a fire will mean you have to break the stone in again. Particularly old stones taken from ruins or abandoned cottages might function as magic items that give extra bonuses.
Stars & Weather
This is an idea that just occurred to me. It seems that when we camp is when we notice the sky. I'm sure this is more because we live in post-industrial places with tons of light pollution, but then we are the players of this game. So, what would looking at the stars do? Maybe a chance of auguries, like comets or supernovas. Maybe some kind of weather mini-game that would determine or allow affecting the weather of the next days travel. Maybe a place for the DM to parcel out little bits of campaign world lore "That constellation is called the Hag because . . ." I don't know, something to think about.
Once you introduce the campsite and these mechanics, they become things you can leverage as class knowledge or feats gained by level. Here is a post where I do some of that for fighters. Undamaged gear shown attention might get bonuses. Special recipes are something characters can learn and can give bonuses above general food gathered or hunted. Bonuses for well chosen sites, and even time to reorganize packed gear can become tasks with meaning in the game.