>>/83421/
In my personal experience, I just started fighting back whenever they got physical with me. Punches, kicks, throws, etc.. I never initiated, just defended myself. With bullies, just the reminder that you're not just gonna sit there and take it, is sometimes enough for them to not even try.
What kind of retaliation are you worried about?
And again, legal disclaimer, I'm not advocating any kind of violence towards anyone.