Have everyone sit in armless chairs (like your kitchen chairs or dining room side chairs) with the chairs arranged in a circle. Everyone is facing into the circle (ie., you're looking at each other). You start the game by holding a pair of scissors and pass them to the person on your left while saying "Crossed" or "Uncrossed". What this indicates is whether your legs (or feet) are crossed or uncrossed. (When people sit in armless chairs, they try to sit up straight and sit comfortably and they will have their legs - or feet - crossed or uncrossed at any given time.)
However, DON'T TELL the rest of the group what "Crossed" or "Uncrossed" means - they have to figure it out for themselves as the scissors go around! That's the fun!
People will assume the scissors themselves have something to do with "Crossed" or "Uncrossed" (like if you hand it off point first or holes first), or maybe if their arms are "Crossed" or "Uncrossed" while the scissors are being passed, etc. It's fun to watch who figures it out first and who takes awhile.
As the people figure it out, they can say they understand, but don't tell the secret! YOU can watch the people to see if they pass the scissors with their feet or legs properly "Crossed" or "Uncrossed" and say the proper "position" to confirm they actually do understand - but don't tell the rest of the group what it really means!!
The game ends when everyone has figured out what "Crossed" or "Uncrossed" means - or the clueless friends can't take it anymore!