Red Light, Green Light mixed with Capture the Flag.
The kids are divided into two groups. One team is the ninjas, the other team is the guards. Ninjas have a place where captured items go; a rock, Ninja base, etc.
Each guard places an item on the ground within the boundary created. They can hide it minimally, but like in capture the flag, it must be able to be seen from at least three directions. They can stand no closer than ten feet from the object they are guarding.
The object for the Ninjas is to get all items back to base without getting caught. The object for the Guards is to capture the Ninjas that are taking their flag or Ninjas trying to get back to base.
All the kids stand still then a counselor says "go". The Guards close their eyes and the Ninjas try to pick up as much stuff as possible by stalking and creeping into the guarded territory. Periodically (every 10 to 45 seconds) the counselor yells “Alarm” and the guards open their eyes and try to tag the Ninjas as they flee to the base. If the Ninjas get tagged they go to the Guard jail where they wait to be rescued.
A Ninja needs to get to the jail before the counselor says, “Alarm” in order to free the captured Ninjas. If the Ninja gets back to base before they are tagged they are safe.