These days it seems like almost every game has tacked-on multiplayer. In fact, it can often be seen as a brave decision for a developer to only feature single-player, considering the extent to which a multiplayer mode can artificially extend a game's lifespan. Sometimes though, we can't help but wonder what a game would be like if we could play it with others. Certain campaigns just feel like they would be tremendous fun to work through with a friend, and some games feature combat mechanics that could really lend themselves to fierce competitive play. Others just have the potential for player interactions that could add a whole new dynamic of fun to the title. For the games on this list, a multiplayer mode might not have been a practical decision from a development point of view. A vast amount of work is required in crafting a decent single-player campaign, and diverting resources to create the game with multiplayer in mind can often result in less than impressive solo experience (just take a look at the more recent Call of Duty releases). If adding multiplayer had no impact on the rest of development though, then we'd have loved to see support within the games on this list.
