One of the most important choices of a designer makes at the start of a project is whether to make a turn based game or a real time one. Each type of base game mechanic provides potential benefits and drawbacks. While turn based games favor more strategic and transparent play, they can feel a little stodgy to players used to action-oriented titles. Real-time games, on the other hand, are more immersive and multiplayer-friendly but can also easily overwhelm new players if not well-paced.
Turn-Based games, of course, descend directly from the board game tradition, predating video games. Indeed, the fanbase for turn-based games still overlaps significantly with the fanbase for board and card games. Real-time (excluding sports), however, were only trutly possible with the advent of computers. Quite a few games – Super Mario Bros., Team Fortress, FIFA, Pac-Man — could only ever conceivably be developed as real-time games.
There are quite a few games that could go either way though, with an understanding that each path comes with its own set of trade-offs. Rouge-like dungeon-crawlers, for example have been made as both turn-based and real-time games. Early versions such as NETHACK, were purely turn based; the game’s clock only moves forward each time the player takes an action. However, Blizzard’s Diablo put the same explore-and-loot formula into a real-time environment and created an experience that was less strategic but more visceral and potentially addictive. Furthermore, without the waiting inherent in a turn-based system, the designers could develop a viable multi player mode.
Nonetheless, Diablo has not supplanted the continuing popularity of turn-based rougelikes, such as PokeMan Mystery Dungeon or Shiren the Wanderer, which maintain thier own tactical charm. Thus, deciding between turn-based and real time is not a question of which system is better or worse, but rather a question of which set of trade-offs best fits the game designer wants to make.