Hi Rosa,

A half court game is easy to set up, you will need a minimum of 8 players. As shown in the diagram below, 4 players will be attackers taking the C, WA, GA and GS positions, whilst the other 4 will be defenders and fulfil C, WD, GD and GK. The C will take the centre pass as normal, however, if the ball goes off the back line or the defenders get a turnover they can have the opportunity to take the ball halfway to score a point. You can then keep track of which team wins - either the attackers or defenders.  

If you have more players you can add a backup WD who will be on the attacking team and have a defensive WA marking them.  

NOTE: if you have 7 players you can still do half court, the C would just be unmarked. 

Hope this helps.