Garnett Lee of Garnett on Games on exclusively multiplayer vs. exclusively single-player games:

We still have vestiges of the prior generations where it’s just sort of natural for those us who have been playing games for a long time to think of single-player as “the game” and multiplayer as “the extra you get with the game.” I think that that influences us at times. However, I think that there are a number of multiplayer only games that you can point to that are very, very successful as stand-alone multiplayer games beginning all the way back with Team Fortress 2.

I was really hoping Garnett would have mentioned early dice, board, or card games.

Games require two or more players. The term “player” is embrued with human characteristics. We often forget that games can not only involve challenges with other humans but also ourselves, computers or luck. Single-player video game experiences are multiplayer experiences against computers.

From solitaire to geopolitics, humans enjoy games. We enjoy games because there is a level of risk and challenge involved that (typically) does not seal our fate. There is variety in experience, chance and strategy. If a single game provided the same experience over and over again, it would become boring. Single-player video games provide humans with a computerized variety of ways to enjoy games in solitary fashion; new mechanics, settings and competition are introduced over the course of a single game and my vary with each play-through. Online multiplayer experiences allow for the same type of human variety that is experienced when playing a dice, board or card game; the receptive mechanics, settings, and characters are a shell for a battle of experience, chance and strategy.

Exclusively online multiplayer is a remote evolution of human-to-human competitive play; however, all games are between multiple players. It is not a debate of “single-player” versus “multiplayer” game design as all games are multiplayer. It is simply a debate of preference between solitary and communal. Not all video games need to played against a computer; not all video games need to played against a human.