This is an idea that came from Red Dwarf, a sci-fi TV show that I watch regularly. I decided it would probably work well in Bloodbowl so here it is.

Set up two games side by side using all the normal rules. Take into consideration the fact that the teams at the same end on either board will be playing together.

One board will be the ceiling, it doesn't matter which, and the other will be the floor.

The teams at the same end are allied together, playing as though they are one big team.

At kickoff, the team which is kicking chooses whether they will kickoff on the ceiling or on the floor.

Once the game is in progress, the receiving team moves first, as normal, followed by the team allied with the kicker, followed by the team allied with the receiving team, followed by the kicker.

Players may move between the ceiling and the floor at a cost of 3 squares, and may pass the ball between ceiling and floor with a one band range increase.

A touchdown can be scored in the endzones of either board.

The game is played out as normal.

You may find this works better with two balls or maybe even more.