Let's consider a case when there's a game with three 15 level character and one 1 level. What will happen with monsters and experience in this case? I am talking about local co-op on the same screen, not multiplayer.
I mean what level of monsters should we expect? Will it be playable for both types of players (for example, 15 level monsters I guess will one shot the 1 level character)?
And how much experience will be getting by 1 level character? 15 level characters? How fast will they balance in levels?