In one sentence, describe what the following article is about:

They will carry a torch. Find an area or object the guard has to protect. The darker, the better. This should be done slowly, while carrying the torch (off).  It may only be turned on for 3 seconds at a time. Say the name of the person you've caught—if you're right the person is out (or must return to the beginning, your choice), if you're wrong they can keep playing. If there are no ninjas left in the game, then the guard wins.

Summary:
Name one person the guard. Wait until nighttime. Have the guard walk around the area or object. Everybody else is called a Ninja, and must go to or touch the area/thing. If you are the Guard, shine the flashlight when you think you hear/see someone. The game is over when a ninja touches the area or object being guarded. Whoever wins has to be the guard, or if the guard wins, they may choose the next guard.