This is a campaign concept I've been bating around for awhile. It occurred to me in a flash while reading the product description for Columbia Games' Wizard Kings. It's not particularly original; in fact, it's designed to emulate the very earliest campaigns in table top RPGs (thus the title of this post).
First, pick your favorite Old School D&D system. I think OD&D works best for this, but any with some guidelines for stronghold building at Name Level will do. Then, get a hex based wargame such as the aforementioned Wizard Kings. Take the map (or maps) out of this sucker. That is now your campaign world. Populate it very roughly with the cultures present in the wargame. To use my example put an Amazon, Feudal, Elven, etc. kingdom somewhere on the map. Then put down your dungeons/adventure sites. A campaign dungeon would work nice here, but it is definitely not required. Then get a set of miniature wargame rules. Scott over at Huge Ruined Pile has been using Hordes of the Things, so lets go with that for now. Set up army lists for the different cultures you placed on your map based on the hex wargame you chose.
Now, we start playing. Players start their characters as level 1 D&D guys. They play a campaign on your hex map and in your dungeons up to name level. Then those who have reached name level build their fortress/tower/church/whatever out in the wilderness. They then largely move to miniature wargame play, attacking their neighbors and clearing out monsters in order to expand their newly formed barony or bishopric. Eventually they'll have enough land that it's better to represent it using the whole campaign map as the hex wargame it was originally intended for. Battles are not resolved via the hex wargame's rules, but rather with the miniature rules, but otherwise it should function the same.
Players who have become kings can obviously still play the minis wargame, but they can also still play D&D. This can be done either by having the player play a wholly new character, playing an employee of his king, or pulling his character out of retirement in order to face some huge threat caused by sandbox events. Players who are still in the D&D portion can move up to the minis wargame portion. They'd do this by playing the orcs/barbarians/other evil things that the King/Baron must "evict" from the wilderness. They could possibly do the same for the hex wargame.
This method works best, I think, with a metric shit-ton of players; however, I'd imagine you could do this with your home group as long as you have enough to play D&D. The main thing you need is time. This campaign only truly works if you can play in campaigns that last for years. It has a strongly generational aspect to it, and I think one of the pleasures of this type of game would be looting the ruins of the Dwarf hold built by Bob's Dwarf more than a year ago in real time. The best way for this game to work is to essentially play no other game, except for occasional breaks so that the players and referee don't get burned out.
To give an example of how this would all play out, lets use Jim Raggi's Death Frost Doom. If you plan on playing this adventure, but haven't yet, skip this paragraph as it contains spoilers. The referee places DFD somewhere on his campaign map that makes sense for the scenario. The first set of characters who reached Name Level didn't come across the cabin, but some others do. They unleash the undead hordes upon both themselves and the campaign map. Now, those characters who have reached name level have to figure out how to quell the undead threat. As they do so, the D&D players can aid with special missions, or continue exploring the places not overrun by the damned.
I doubt that I'll be using it for Nightwick in the immediate future because I'll have to switch schools in two years or so to get my doctorate. However, once I settle down somewhere I'll probably at least give it a go. Of course I also need to figure out how to get money for the minis it would require.
So that is my proposal. Take it. Leave it. I just thought it was a neat idea.