What are games? This is the sole question to begin to understand how games work. We are going to discuss the very basic design of video games. If you are new to video game design, this is where you should start.
Video games, at their most basic, are divided into two sections based on their design: story and gameplay. In the very best games, these two work together to make a masterpiece. Gameplay should complement story, and story should complement gameplay (you’ll see what I mean in a moment). People discuss story-driven games and gameplay-driven games, but to make a game the best it can be, they should really be the same caliber. It’s time to stop thinking about gameplay and story, and time to start thinking of them as story-gameplay (no, I did not get this idea from Einstein).
Gameplay is, well, you actually playing the game – how you are allowed to interact with the 
world. This gameplay is also divided into two sections: actions and challenges. In Halo, the actions are running, shooting, jumping, crouching, reloading, etc. These actions are referred to as game mechanics, and you are able to do each one in the virtual world by doing something in the real world with the control. Often, each mechanic has its own button. You use these mechanics to complete challenges.
A challenge in Halo is often a hoard of enemies. Challenges are often interwoven throughout the game. For example, let’s say your challenge is to rescue the princess. To do that, you need to get the sword, a subchallenge. To get the sword though, you need to kill the sword’s guardian, a subchallenge of a subchallenge. You accomplish these challenges throughout the game by using the mechanics. The relationship between the mechanics and challenges is what’s known as gameplay. That is pretty much the outline of every game: a series of challenges, or problems, which the player must complete.
The second part of a video game is the story, which includes the story (the events that occur in the game), atmosphere, sounds, characters, and all things that either make the virtual world more immersive or gives weight to the challenges. Let’s say we’re designing a video game, and the player’s overlying challenge is to save the princess. But how does the designer make that the challenge? Do we just say in text, “You’re challenge is to save the princess.”? No! We let the
story give you that objective organically. We can show a cutscene of you and the princess, when she is kidnapped and you are knocked unconscious. Characters of the village can be sobbing about their loss to you; the town may go into disarray, etc. The point is, you, through the character you play in the game, know that you have save the princess. If we just told you in text what your challenge was, you would feel no obligation to complete the challenge. The game wouldn’t be fun, because the game of interweaved challenges has turned into a list of things you have to do. Go from point A to point B, and you win the game. Nobody would ever go to point B just because you told them to. Through story, challenges should be organically produced and given to the player, who now has a reason to complete the challenges. He/she now wants to complete to the challenge because of the story – you’ve become attached to the characters, you want to save this interesting new world, you want to know what happens next or the answers to your questions about the story or world. The feelings the game gives you is also important – you want to continue to feel the power, achievement, etc. You also want to keep playing because the gameplay and process your mind plays in completing challenges, but the story on top of fun gameplay takes the game to a whole new level (no pun intended).
So now about how gameplay and story complement each other. Basically, gameplay should progress the story. By accomplishing your goal, you are rewarded with story. By using the game 
mechanics to accomplish the challenge of saving the mayor who is inside a burning building, he may reward you, in the story, with a weapon, information, or something to get you closer to your larger challenges, like saving the princess. The weapons means new, fresh gameplay for you to enjoy, completion of the challenge makes you feel great, and you get to progress through the story which you’ve been immersed into.
So, wrapping up, story and gameplay make up video games. Gameplay is the actions, goals, and how the two go together, and story is what gives weight to the goals. Gameplay opens up story, as story serves as a reward for gameplay. Story also gives reason for the games, so without story, the gameplay is not as fun or logical.
I could go on forever, but I’ll stop there. It is a lot to process if you are new to game design, so for practice, go play your favorite game (action, action-adventure, or adventure game, although there are many more which use this formula), and examine the challenge structure at any point (know your main goal and all of the subgoals at any point in the game after the introduction). Also figure out what the mechanics are. Also, if you’re in for a challenge, try to figure out why you are playing the game and completing the challenges. What is it about the game that makes playing it so much fun? We’ll cover that someday.
Have fun, and come back later for part 2.
Dylan Woodbury lives with his family in Southern California. He runs http://dtwgames.com, a game design website that posts intriguing new articles every week, both beginner’s tutorials and theoretical ideas. He also has an interest in writing, and is planning his first novel. His primary goal is to change the world through video games.