Go Fer Yer Guns RPG rules. The more I think about it the more I agree with the general conclusion that a western RPG is quite a bit different than a FRPG such as Swords & Wizardy (or the million other FRPGs out there). They're so different, in fact, that there needs to be a whole different process of planning the game.
In a FRPG, it's natural that a group of PCs come together to form a party to go explore a ruin to fill their pockets with gold and trinkets. The more you have in the party and the more diverse the group the better chance you have to survive. You can pull any number of pre-made dungeons, take a half and hour to roll up some characters and in you go, you're playing a game.
A western, on the other hand, is quite a bit different. Most characters would essentially be loners and quite separate. Their goals and desires would be quite different and rarely would they cross paths except, perhaps, in conflict as their goals crossed. Keep in mind, I'm looking at this as an open ended sandbox setting, my preferred method of play - but can a sandbox work in a wild west game or, by necessity, are we looking at a more linear style of game play?
My initial feeling is that it would need to be a combination of both. That can be accomplished with a couple additions to the western game, both of which I found over at he OD&D boards under their Boot Hill section.
The first is character motivation and this comes from Avalon Hill's Gunslinger game (mentioned in the OD&D thread). I don't own the Gunslinger game so I'm just going by the information in the post. Basically a character chooses three out of six motivation for their character (Settle Down, Money, Comfort, Respect, Fear, Outlaw). I would disagree with the post by calling it an alignment system in that both good and evil, lawful and chaotic characters can achieve those goals by different means with the exception of Outlaw. Perhaps I would add another one called Honor to balance out Outlaw. These 'motivations' would give general direction and drive for the character and help the GM (Game Marshal) corral and challenge the players in a sandbox environment. Rewards can be given for characters staying within their desired motivations. Remember, and this is important, these goals can be achieved by being lawful or unlawful - that is up to the character's actions and the GM's interactions.
Second, a western game is driven more by characters and their interaction and less by exploration and killing things and taking their stuff. A great idea in the OD&D post was Mapping out the Adventure based on the NPC's much like how you would map out a dungeon. With the rooms being the NPC's and their connections (relationships) being the corridors players can be 'guided' from one interaction to the next depending upon their goals. To flesh out the NPC's each one would have attributes such as fears (what he will do everything to avoid), desires (what he will do everything to get), and duties (what he feels he must do). These attributes would regulate the NPC and give the PC and GM and idea of what to expect from these characters.
Both of these ideas would aid in getting the western game moving but there's still the issue of what would bring your players together.
When running any RPG it's always a challenge when just a single character splits from the party to go interacting with NPC's by themselves. In a western game it seems that you would have quite a bit more of that. We have about 9 players in our gaming group. I feel that that would be quite a challenge to keep everyone engaged once everyone goes off on their own. Would face to face tabletop play be the best avenue for a western game? Or would something like a play-by-post work a bit better where the players can separate and the GM can interact with all of them individually?
Finally, one solution to that would be to discuss with your players what type of game they would want to play and plan the game play around that. For example, perhaps they all want to be part of a single gang? Well, now they're all together and a session can be planned accordingly. Or perhaps they all want to be part of a posse? Good start, they're all together. Perhaps they are a group of magnificent gunslingers coming together to save a town from bandits? But breaking away from these archetypes in group play may be difficult especially since there would tend to be less 'action' and more 'role-playing' involved.
Apparently there was one more point I wanted to make but had forgotten what it was by the time I got down to the bottom of this post. Oh well, it's Friday. Just enjoy this....