Indoor game of volleyball with an opaque net
* Tie a rope at leader's head height across the hall.
* Put the groundsheets over the line making a net that cannot be seen under, over or through.
* Play a game of volleyball over the net.
You will find it difficult at first, but the quality of play will improve as time progresses. The number of bounces and hits that each side is allowed before the ball must go over the net is to be agreed by the leader before the game.