I did it with Adventures Unlimited. The hardest part was making it in such a way that the two factions just didn't attempt to annihilate one another the moment game on was called. The second was to create intermixing plots that didn't always become a game of capture the flag/beatdown fest. The third was convincing the players that they would lose about 50% of the time (with all things being even).Robb Graves said:i keep thinking about the European larps that have playable villain races and PC wars. If you think about it, an NPC camp, as awesome as it could ever be run, probably could not generate a more developed and greater looking re-occurring villain than a PC could. Perhaps if there were actual PC evil out there trying to destroy the town or whatever, with their own COPs and rituals and perhaps segregated plot, mods and wave battles, it might be a very different game. granted you need alot more people to pull that off and very large grounds to keep the factions apart... but it makes me wonder..
However, when I got over those three humps, it was perhaps one of the most rewarding games I ever ran. Especially since it also cut down my NPC requirements to almost nil. Just had one plot person as the leader of the bad guys, one plot person as the leader of the good guys and one plot person as the leader of the townsfolk (neutral). I then only needed a couple more for extra NPC roles to be filled and more often than not, just worked a storyline with a townsfolk PC and he became the quest giver - not really needing an NPC.