Civilization and Spore designer Soren Johnson explores the separation between the rules of a game and the skin that's applied to them, and argues that a game's meaning always lies in the rules.

On Tuesday morning, Soren Johnson used his keynote at the Serious Games Summit to explore the difference between a game’s mechanic and its theme – between the rules of the game, and the skin that’s laid over them. Johnson argued, “Just because you give a game a theme, doesn’t make a game about that thing. … A game’s mechanics give it meaning. It fundamentally does not matter how you theme a game, the mechanics ultimately determine what a game is about.”

Johnson, the designer/programmer at EA2D who is best known as a designer and programmer on titles like Civilization III and IV and Spore, gave examples of the distinction between a game’s theme and its mechanics. He compared the board games Risk and Diplomacy, which appear similar on the surface but whose rules deliver different experiences. Where Risk lets players take sequential terms and watch each other’s actions, Diplomacy forces players to guess what their competitors will do. Risk uses dice during battles, while Diplomacy has no elements of luck. For two games about world conquest, the games’ meanings are significantly different – or as Johnson summed it up, “Risk is about risk. Diplomacy is about diplomacy.”

When a game’s theme conflicts with its mechanics, it risks disappointing the players. Johnson, who was lead gameplay programmer on Spore, discussed the mixed reaction the game received after its launch. While Spore had been billed as a game about evolution, the game’s real appeal lay in its creature creator – a tool that had nothing to do with the laws of evolution. Quoting a Science magazine article that stated, “Spore failed miserably” as science, he argued that other games have modeled the theory of evolution more effectively – for example, World Of Warcraft, where players optimize builds for every class, creating characters that are not unlike the specialized finches studied by Darwin.

Johnson gave several other examples: ““Super Mario Bros. is actually a game about timing, not about plumbing. Peggle is about chaos theory, not unicorns.” Battlefield 2 and Left 4 Dead are both about team work, but they apply different themes to the mechanic. “Here you have two games with very different themes that are fundamentally about the same thing.”

Johnson delivered the talk as the keynote to the Serious Games Summit, and he used the opportunity to explore the problem of bringing realistic themes to games. “Often when you choose real-world themes, you hit some limitations because people come to the game with expectations about how something works. In Civilization, you have that problem: archers should be this. The pyramids means this. It’s a blessing and a curse. This is why a lot of game devs decide to go sci-fi, because they can twist the game thematically all they want to support the mechanics.”

While Civilization has been viewed as a game about world history, the mechanics make unrealistic assumptions in the interest of good gameplay. For example, real emperors delegate authority; in a game, players want absolute control. A civilization on a given continent may have grown without horses, but taking them away in the game frustrated players.

Johnson listed several examples of games where the theme and the mechanics were in sync. He praised The Redistricting Game, where players are encouraged to gerrymander political districts and to reach results that are just as convoluted as real-world examples. But overall, Johnson recommended that designers who wanted to explore real-life problems should consider avoiding the constraints of real-life – for example, by taking the “Star Trek” option of setting the game in a made-up scenario. He also recommended focusing on the struggles of an individual, instead of modeling a society. “I think this is the way forward: you want to play a life. Put the player in the shoes of someone who really existed, who had real tough choices to make in their life.”