- Aha - so John H's second in Gamasutra's 'Game Design Essentials' series, following '20 Difficult Games', looks at the roots and design lessons of 'open world games' - titles in which the player "is left to his own devices to explore a large world" - from Adventure through Metroid to Grand Theft Auto.

Here's something from his intro, helping to define the tricksy term: "When we discuss "open world games" in this article, or sometimes "exploration games," we mean those games where generally the player is left to his own devices to explore a large world. What all of these games share is the seeking of new, interesting regions at whatever time the player deems fit. No force forces the player's motion into new areas. There's no auto-scroll, and there are no artificial level barriers."

The whole article is a little retro game-focused, sure, but as Harris says, design mechanics are often much more clearly delineated or oddly exposed in those earlier titles - and I like his discussion of the classic Adventure on the Atari 2600: "Adventure's fun comes from the way all of its simple objects interact to produce complex behavior... carrying the sword, the bat might brush it across a dragon on his flight, killing it. This is possible because all of the objects in the game function automatically, which they have to be anyway since The Button is devoted to dropping stuff. A lot of the fun in Adventure comes from the unintended consequences of the player's actions." Chaos can be fun!