Yes, what a game is, that's something that will take us a long time to understand, fortunately. But one of the parts of a digital game is interactive narrative, and reaching a good narrative should be the goal of us game developers. With a new definition of "game mechanic" we can now have a new set of tools that eases our work. Getting closer to good interactive narrative requires a new step in the stair, and that is a second-layer game engine. First-layer engines manage communication, then second-layer engines will manage options. That's one little step further to master the abstractions of interactive narrative.
Games already manage options, but remember what happened when first-layer game engines appeared, how these changed game development. Developers obtained the tools to achieve better game<->player communication. Now a second-layer game engine will provide a foundation to build more advanced game mechanics. Developers will be able to focus even more on the creative side.
Not only we can have a new definition of game mechanic, now we can talk the language of game mechanics, and second-layer game engines are approaching.
EDIT: This is the definition of game mechanics from Ernest Adams and Joris Dormans book:
"The video game design community usually prefers the term game mechanics to game rules because rules are considered printed instructions that the player is aware of, while the mechanics of video games are hidden from the player, that is, implemented in software for which the player is given no direct user interface. Video game players don’t have to know what the game’s rules are when they begin; unlike board and card games, the video game teaches them as they play. Rules and mechanics are related concepts, but mechanics are more detailed and concrete. For example, the rules ofMonopoly consist of only a few pages, but the mechanics of Monopoly include the prices of all the properties and the text of all the Chance and Community Chest cards—in other words, everything that affects the operation of the game. Mechanics need to be detailed enough for game programmers to turn them into code without confusion; mechanics specify all the required details.
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Game designers are perfectly comfortable talking about a game mechanic in the singular form. They don’t mean a person who repairs game engines! Instead, they are referring to a single gamemechanism that governs a certain game element. In this book, we prefer to use mechanism as the singular form indicating a single set of game rules associated with a single game element or interaction. One such mechanism might include several rules. For example, the mechanic of a moving platform in a side-scrolling platform game might include the speed of the platform’s movement, the fact that creatures can stand on it, the fact that when they do they are moved along with it, but also the fact that the platform’s velocity is reversed when it bounces into other game elements, or perhaps after it has traveled a particular distance ."