All games have a certain flow; this defines what the players can do in a certain part of the game. It is called a game-screen flow diagram. A game-screen flow is an overall flow of the game that shows everything the player can do in the game. An example of a game-screen flow diagram is as follows:
The preceding diagram is a flowchart that represents the flow of a game from start to finish.
It might look confusing at first, so let me walk you through it.
- Every diagram starts at the... Start node (surprise!), and the Start node always branches out into one screen, and never more than one.
- The first screen is what is presented to the player for the first time; in our previous diagram, it is the title screen, but you can show other screens if you want (an intro animation, maybe?).
- After that, we are presented with a question: does the player click on the quit button or not? If yes, then the game quits; if not, then the game still continues.
- From here, it can branch out into several different screens; what is displayed to the player is represented by the Display node.
Note
If you noticed, the arrows between the screens are of two types: one-way and two-way arrows. These indicate where the player can go from a screen; sometimes they can return to the previous screen, but sometimes they can't.
The reason some screens are not linked by arrows of any sort is because they don't change screens, such as the connection from the Show options screen node to the Changes sound volume node.
- Take a look at the options screen; it branches out into three different nodes. These nodes indicate what the player can do inside the linked screen. The three nodes are changes sound volume, changes difficulty, and changes game control.
- From the level select screen, we can go to the main gameplay screen. However, from here, we can't directly go back to the level select screen; we have to go to a Decision node.
- Here, the question is has the player won? If the player has won, a victory screen is presented before going back to the level select screen; if not, then the gameover screen is shown.
Tip
Remember that this diagram only shows what the players can do and where they can go. It doesn't show what the game automatically does. For example, in the victory screen, the game might unlock the next level if it is still locked, and in the title screen, the game automatically plays the background music.