Every project and every game design is going to change. One of the goals of object-oriented programming is to program with that change in mind. This means writing flexible and reusable code so that, when changes happen, the project doesn't fall apart. Unfortunately, the requirements are never fully known and the vision of the designer is never 100% complete. The good news is that newly added features may interact with old features in unexpectedly fun ways, leading to unplanned features being created, which can make for a completely different, and more enjoyable, game.
In the worst-case scenario, the game design may not be fun at all, which can lead to drastic changes in game object types, object behaviors, and even the design of the entire game. In this case, we want to be able to rework our game to try new possibilities with the least amount of change to code...
