At the start of this chapter we saw three problems with interacting gameplay code. As we said before, these problems aren't that big, but they creep up all over the place and can lead to inflexible code as the project moves forward. The Observer pattern solves these problems in a very simple way.
The biggest benefit of using the Observer pattern is that we can reduce dependency and coupling. By using the Push version of the Observer pattern, our classes can interact completely through interfaces, so they don't depend on each other at all. In the preceding example, the Player and Player Display are completely decoupled. This means that changes to one won't affect the other. For starters, this makes each class easier to test and debug because they can be worked on separately. However, this also means that as the game changes, these classes can change independently...
