Having various types of missions for both a single guild, or many guilds to participate against one another and having some explicitly for certain categories. For example, a cooperative mission may be something like a last stand where you and your guild hold out against waves and waves of enemies until each member has fallen for as long as possible (this may also be counted for competitive if a leader board is kept). Then you may have a competitive mission, for example, where two guilds must compete to gather a certain amount of 'object' to win, before the other guild (again, leader boards may be kept to see who is most consistent). The idea is not to have these be about money, or any other prizes. But to suit both the people who play for competition and the people who play for leisure, just as an activity for the guild to participate in for fun. However, if done successfully it will create long term benefits for both groups to have fun. As for the possibility for incentives, I would strongly disagree with the idea that gralats or any other reward for playing should be given. To motivate the competive players to continue, a 'Guild Olympics' perhaps can take place annually, and guilds would be responsible for diving their members into teams per challenge (if they choose).