You need at least two people who already know how to play the game.
Play begins by one person saying "I'M GOING ON A CAMPING TRIP AND I'M GOING
TO BRING...(at this point the person talking picks anything s/he would like
to bring on the trip. Let's use a sleeping bag as an example) A SLEEPING
BAG". The next person says "I'M GOING ON A CAMPING TRIP AND I'M GOING TO
BRING...(at this point the person talking picks anything s/he would like to
bring on the trip, but it must begin with the letter "G", since the last
letter of the first person 'camping accessory' was a "G". For example let's
say the second person wanted to bring a "GUARDIAN" they can bring that so
everyone says "OKAY YOU CAN BRING THAT ON OUR CAMPING TRIP". Say the third person hasn't caught on to the game yet and says, "I'M GOING ON A CAMPING
TRIP AND I'M GOING TO BRING HOT DOGS". Everyone should say, "NO, YOU CAN'T
BRING HOT DOGS" and play continues to the next player until everyone has
caught onto the game.
Contributed by Janet
Once a player thinks they have figured out a rule, they ask the first
player whether or not they would take a certain item to verify their idea:
Play continues until everyone gets the rule figured out. Then someone else picks a rule and a new game begins. The rules can be anything, and are only limited by the creativity of the players.
[P.S. the rule in this example was double letters]