Game design. What is it? Let's break it down.
Normally when somebody thinks of game design they think of creativity, brainstorming, and/or critique. Pretty aesthetics, good decision-making/rules, and the underlying foundation of a game to make said game look and function its best. To be fair, that's not completely off the mark, though it's MUCH deeper than that. The term "game design" is very broad and vague. It is generally said that a game designer is "a cross between a writer, artist, and programmer." Another source breaks down the roles of a game designer as content designer, level designer, systems designer, and experience designer. What I'm trying to get at is that it's both technical AND artistic, plus there's a lot to accomplish in this field, much more than meets the eye. A simple example of a design choice would be to include suspenseful music in a dramatic scene rather than a cheery one, and another team would create the theme based on that decision.
Fundamentally, overall game design relies on creativity (and design, of course) to attract players and keep them engaged in the game's content since the player is the prime focus, similar to a business's customer focus. Speaking of which, game designers have many responsibilities to tackle since there's a lot to handle in a game. From refining a game's purpose, its varying mechanics, plot, core concept, character design, balancing, and more, to make a game look exactly the way it needs to be. Ultimately coming down to level design, world building, story writing, user interface design, and most importantly, system design. Another quality usually undervalued but VERY important would be communication to help properly express ideas across to others, along with staying organized and documented.
Now to the steps of making a game, because there's information to keep in mind. Just like the Scientific Method, creating a game can be created similarly. Many steps can be repeated over and over again to get a game exactly where it needs to be. The pictures/processes below help demonstrate what this may look like. As a Plymouth educator has said, "the more times you iterate, the better your final game will be." Now, a brief summary of several concepts to review often; direction, behavior, progression, environment, method, and foundation (including how the player is factored into the game and the communication from the game to the player). All concepts and applied principles are here to help aid in game designing: here.
To wrap things up here, game design is a generalized term to describe the many roles and responsibilities in game development decision-making with system design at its core within this class.