First of all, the reason WHY we want players to organize into mobs and fight each other is because they will do it regardless of our efforts. People have an inherent quality of forming groups, and this is something we can absolutely rely upon. There's nothing that will make the individual feel more proud than a display of power justified by a supreme authority. Therefore it is only smart of us to provide them with a number of templates for this purpose. Of course, one could argue that communities only exist in our heads, and are formed through communication and such, but we can't rely on every player being able to role-play to such challenging extent. Besides, people form nations, churches, families, tribes, cities and whatnot all the time. They have names and definitions for their groups and organizations. We must be able to provide the players with the motivation that accomplishes this. And that's where the "how" comes in.
	
	Player community systems should be hard-coded into the gaming system. Period. A gaming system where people would be a part of something upon verbal agreement would have a rather shallow identity, and the individual members would have very little to identify with (to be proud of). Just like in real life, each community must have a name and a purpose. Its own unique habits, values and such. The real challenge here lies in providing the players with the proper motivation that is needed in order for this to succeed. Some proposed initial ideas are:
	
	*Religions. Religions form churches. Churches have a very strong identity, because it is directly dictated by a god. Therefore, it is always righteous, and everyone who disagrees with God's teachings is a heathen, and should be cast down from his arrogance! Of course, this route is not necessarily enforced by all Gods with the same intensity, but as all Gods rival each other and want power, this will always happen to some extent. Concrete motives for religious groups to target each other, apart from the fun part of killing infidels, would be that their God would reward them. Rewards can be such things as items, higher positions in the church that will yield more spells and better types of praying, permanent blessings of various types (these could affect stats, skills, or even give the players new abilities that mortals don't usually have, such as levitation or invisibility).
	
	*Races. Concrete motives of races rivaling each other wouldn't only be about playing roles, it would also be about convenience. As players might not know each others' languages for example, the only way they would be able to benefit from each other would be killing each other and stealing each others' items, blueprints etc. Maybe, like in Dark Age of Camelot, we could contribute a number of relics for different races. These could be very powerful items that affect the owner race in some manner. A good enough reason to pursue all orcs would be that maybe, just maybe, that big orc over there has the magickal Supreme Orb of Orcish Rule +5 willpower. Cities of different races could also have war standards (flags) and such, and the standards in a town could improve it's features, like food production, level of npc guards etc, somehow in addition to being trophies etc.
	
	*Schools. Because skills are taught by masters to disciples, we will have several masters or teachers who have a whole bunch of loyal apprentices. There are many skills in Majik that can/must be learned from other players. Such things would include unique combat styles, magic, artwork, craftsmanship etc. These would form groups that would jealously protect their trade secrets ... and prevent anyone from abusing them. This is contributed to by players of different cultural backgrounds having different initial skills and item creation blueprints. The motives for masters to rival with each other could be, in addition to glory and fame, that people would have to pay membership fees to join these groups, and all members, especially teachers, would profit from them. Also, the benefits of a large school would be high availability of training (more people would join) and high quality of training (people would stay once they have joined).
	
	*Spheres of Power. The Truename spheres. These humongous orbs are a real treat, because they can change ownership rather quick, can easily be protected, and have a very concrete and well-defined use (learning a true name is only possible with these orbs). I can well imagine people looking after these.
	
	*Houses. These could be formed by players who have "real life" connection with each other, or for some other not-so-well-defined reason. They would have little or no specific purpose, but they would have a very high sense of identity and a very high state of companionship. They would rival among each other just because the heck of it.