I guess I'm thinking that if you react physically each time, you'll get a reputation. If you react to on-going torment after 2-5 incidents, you may do enough to dispel the physical harassment without getting a reputation as a thug.

I was bullied in the early years of high school (age 13-14 mostly). I didn't really think of it at the time, but the worst of it probably stopped around about the same time that I grabbed a guy around the neck and dragged him to the ground.