How do you make a player do damage to another player?

One of my students published the game "Cowboy test" today but she cannot get the weapons to do damage against the other players in the game. Can anyone suggest how to fix this?

If you are using the standard Core weapons (Core Content Tab, Game Objects - Game Components - Weapons) then you should be all set. Do you have a Team Setting component (Core Content Tab, Game Objects - Settings Objects) set to Free For All? Or if team based, are you correctly allocating player teams?