After reading the chapter about formal elements, you should note two things.
First, if you change even one formal element, it can make for a very different game. Each formal element of a game contributes in a deep way to the player experience. When designing a game, give thought to each of these elements, and make sure that each is a deliberate choice.
Second, note that these elements are interrelated, and changing one can affect others. Rules govern changes in Game State. Information can sometimes become a Resource. Sequencing can lead to different kinds of Player Interaction. Changing the number of Players can affect what kinds of Objectives can be defined. And so on.
Because of the interrelated nature of these parts, you can frame any game as a system. (One dictionary definition of the word “system” is: a combination of things or parts that form a complex whole.)
In fact, a single game can contain several systems. World of Warcraft has a combat system, a quest system, a guild system, a chat system, and so on…
Another property of systems is that it is hard to fully understand or predict them just by defining them; you gain a far deeper understanding by seeing the system in action. Consider the physical system of projectile motion. There is a mathematical equation to define the path of a ball being thrown, and you could even predict its behavior… but the whole thing makes a lot more sense if you see someone actually throwing a ball.
Games are like this, too. You can read the rules and define all the formal elements of a game, but to truly understand a game you need to play it, usually more than once. You need to see how the various pieces of the game system interact with each other given different game states. Only then can you understand how the game system might be improved.
This chapter was adapted from Level 3 of Ian Schreiber’s Game Design Concepts course.