So last night the magic become!! The first problem was the number of players (8); we knew the game it would have been very long, but we don't complaining about. With this number of wizards, we decided to play a Deathmatch with 2 teams of 4 players each others.
The second problem to fight with was the map and the presence of portals: we decided to place they randomly on the map, but after all it wasn't a good idea. Like another game played last years, placing portals into the map and not at borders make the game very confused, and it not provide some real improvements.
The third thing is the deck: we choose to play with a deck for each team (good), with a base cantrip and 4 schools (non so good, better stay with official 3 schools-decks), where schools were drafted by every player (good, but the players must know something about schools rosters, and the team MUST talk each other about an idea for the deck and playing style)
The game, like any other DM, became very long, with about 4 hours of play, and we must rethink the turn system, because when a team lost a player the change of turn order it can be very problematic to manage.
After all, the game was very enjoyable, and everyone has fun. The map it was very big, and a lot of free spaces reduce the role of creration-trap schools, like Hexes (one of our team "garbage" school), but for eight players it was good.
