Stand in a circle. Each player puts a right hand out flat with palm up. Each player then puts left hand index finger pointing down touching the palm of the person on your left. Now everyone is ready. Someone who is in charge of the game calls out "One, two, three". On "three" everyone tries to do two things. You trying to pull your finger up to keep from getting it grabbed, and you try to grab the persons finger on your right. If you pull your finger up before the host says "three" then you are OUT! You must move out of the circle.
There will usually be a few that get caught each round. If your finger gets caught then you are OUT! You must move out of the circle and the circle gets smaller. Then the next round begins. Everyone assumes the initial position and the game continues.
Regarding counting: The person doing the counting always counts to three, but they can use different timing. You can go fast "Onetwothree" or slow "One Two Three" or you can put spaces in between such as "One two (wait a second) three". It's important to mix it up to keep the players on their toes and paying attention.