The group is divided into two equal halves, ‘Soldiers’ and ‘Sailors’ and they are at each end of the room.
The leader calls ‘Soldiers Advance’ and all the soldiers take a step forward, then ‘Sailors Advance’ and the sailors take a step forward. This is repeated until they get close or even pass each other. The leader may also call ‘Soldiers [or Sailors] Retreat’ and they step backwards.
At an appropriate time the leader will call ‘Soldiers [or Sailors] Attack’ at this point the side that’s called, catch as many as possible of the other team before they get back to their end. The leader can decide if ‘catch’ means just tag, or more boisterous, haul their captive back to their end.
The game finishes when the leader decides they have had enough or one side is totally caught.