More and more games are using dynamic physics to add to the gameplay or as a core element of the gameplay. Box2D is a popular and powerful physics library that is considered to be one of the best 2D physics libraries around. It is used by high profile games like Angry Birds and Crayon Physics Deluxe. This tutorial will focus on the Flash version of Box2D and assumes that you have basic experience with Flash and ActionScript 3. If you are new to Flash, check out Nandrew’s excellent Flash tutorial.