What is Brazilian Jiu-Jitsu?

Think of BJJ as human chess played with your body. Two people grapple on the ground, each trying to outmaneuver the other using technique instead of punches or kicks. The magic of BJJ is that a smaller, weaker person can defeat someone bigger by using leverage and positioning. You win by making your opponent "tap out" - a signal they give up because you have them in a choke or joint lock they cannot escape.