I'm starting out learning to build games in Phaser and doing multiplayer games and had the idea that I would build a simple multiplayer game to play with the kids. the basic idea: Two teams of either 1 or 2 players each kick a ball around a bounded area trying to get it into the opposing teams goal. I've played around with the physics engine demos a little bit and think I know enough to make a player (circle) that can move a ball (another circle) around in a Phaser game using P2 physics. I've also messed a little bit with node.js and the sockes library and implemented a little demo of setting up a server for multiplayer. Now I have gotten to the question of how to handle the physics in a multiplayer game. It seems to me like the physics simulation should be running on the server but how do you do that? Do I run a Phaser instance on the server to simulate physics or do I choose a standalone physics library and run that on the server? Bonus question: If physics is being simulated on the server do I need to run any physics on the client in this multiplayer example?