When somebody is knocked out, one person should lift their legs to help redirect blood flow from the extremities to the upper body because the brain will need the blood flow. Somebody else should be making sure their airway is open so that they can breathe, you can do what is called a head-tilt-chin-lift to accomplish this. Just press on the forehead and lift the chin so that the tongue doesn't block the throat (they'll probably be snoring if their airway is blocked). Talk to the person to try to wake them up. If they don't wake up, try pinching their trapezius hard to see if the pain causes them to react. If they don't react, call 911. Try to have somebody around that can perform CPR just in case (you should really be doing this with instructor supervision).

A knock out is a side effect of a concussion, in most cases the longer the person is out the more sever it is.

G4p mentioned some important steps but after that the person should see a doctor. To determine the severity of the concussion

You and your friends should not be doing this. I would not recommend anything like this unless all parties involved are black belts AND are over the age of 18. In some cases, I still would not recommend it.

Let me put it this way: if you cannot do it in front of your parents, you should not be doing it.

What you are not considering is that someone can get knocked out, hit their head and die. They could have some sort of underlying health condition that gets aggrevated in the fight group, leading to a death. Considering that people can get killed in sanctioned, supervised sporting events, you should realized that an unsanctioned event is actually more dangerous. Is it worth risking your friends lives in the name of something you think is cool or fun?

If you want to fight, join a martial arts club or school that competes a lot, take boxing, take MMA, take wrestling. At least in those competitions, there are medical people who know how to handle things if someone does indeed get knocked out.

Try to avoid getting knocked out. Learn from his mistakes.

Try to wake them up. Have fun haha

Stand over the top of them and in a Chris Tucker voice say. " you just got knocked the **** out!"

Take his wallet.

So my friends and I are having fighting group (for fun). We are going to wear head gear, like the sparring headgear that covers the jaw and the top of the head. So what would we do if someone were to get knocked out?