This is probably the most important part. If you haven't already been doing this, then I would suggest that you stop what you're doing and start. Testing is such an important step in the process because it helps to make sure that your game runs smoothly and efficiently. Not only this, it can raise issues relating to player engagement, glitches/bugs/exploits within your game that can give other players an advantage when it comes to game time (especially in multiplayer games). We will cover playtesting in a later chapter, so we won't go into too much detail now.