Minecraft wiki entry for Player_versus_Player, associated text: "Organized PvP" would be a non-free-for-all and small-amount-of-factions PvP. Suppose there are only 2 factions, one is evil and one is good (or they are neither). Below are some tutorials for if there are only about 2-4 factions (recommended for only 2 factions) and is a very organized player versus player. This could be useful if there happens to be a ranking system on the server. It is also recommended for lots of players to play at once. It would be good to mark the team you're on your structures so you don't accidentally wander into an enemy's base and get yourself killed.