Children in grade school have an incredible number of mean tricks that they used on their uninitiated classmates. Most of these tricks only work well once, for instance you only join The PEN15 Club once, and after that you probably won't let anyone write on your hand (or head) again. Others however like the veritable wedgie or snakebite can be applied quickly and efficiently, preventing any sort of retaliation. The only solution is a pre-emptive strike, wedgie them before they wedgie you! Some other popular tricks include:

Just to name a few.