A fight as dream image usually stands for a strong conflict taking place within yourself, maybe between reason and subconscious or between the rational and emotional sides of your self. You need to find the most appropriate solution to this inner conflict before you can move on with your life, or else you will not be able to achieve a general equilibrium.
Seeing a fight in your dreams may also mean that you are worn out, overstressed and you could really use a break, a moment to calm down, relax and repose.
Fighting may also be interpreted as a sexual dream symbol. It may stand for too much sexual energy accumulated inside you or for your primitive sexual urges which tend to break the surface of reason.
To see or take part in a fight in your dream may also represent hard times you are going through in real life. To see a battle in your dream but not taking part in it may stand for your fears and anxieties, especially when it comes to dealing with responsibilities and difficult problems in your waking life. If you take part in a fight and you or your group is victorious, then you will manage to overcome all obstacles and deal with all difficult problems in your waking life. If defeated, it will be rather hard for you to be successful when facing life issues.