If you are a bystander to a conflict, two things you can do to prevent a fight is to ignore people who make negative remarks; refuse to spread rumors; and stay away from an area where a fight might break out. What is a fourth thing?
Gather your friends to cheer on the person you want to win.
Do not relay a threat or insult from one person to another.
Dare both sides to back up their words with action, and have it out.
Be sure to keep both people informed about what the other person is saying.