There is some experience about playing in group in Dofus that came from other side. Maybe it will help you.
Information about Dungeons and their keys is a question which most people want to know. Even unique or extremely rare creatures are hiding there and protect wonderful treasures, but it is a long way to go before you will get there as you will have to find the appropriate key first. You need not worry, the reward, such as dofus kama will be worthy the effort. For instance, a Gobball will drop the Gobball Dungeon Key. Dungeons almost have one single species of creature. The Gobball dungeon in only populated with Gobblies, Gobballs, Gobball War Chiefs and a Royal Gobball. It is a series of rooms full of creatures. You will have to defeat all the creatures of each room before you can move to the next one, as you will move up so will the level of the creatures. What you can do is waiting for other players to join you and create a team enough to fight the creatures without dying in the first round.
How to create a group? You need to do is click on a character which is not yours to create a group, and then invite this character to join your group. The playable character you have just invited still needs to confirm and accept your invitation. At the same time, you can decide to dissolve the group. All you need to do is click on leave the group in the interface in the right hand corner of the screen.