Game developers are finding that the simplest way to provide a deep game is to program a wide variety of simple things and let the player create complex situations with them. For example, imagine a game the where the player has to cross a river. The water is programmed to act like water and so are any of the natural elements in the game. While in a normal game the character would have to, say, push a button and lower a bridge, in this game the player can build a dam with stones and sticks from the environment of build himself a raft. It may not be the easiest way to do it or something the developers intended but since all the objects are useable the player can do anything they want. This is called emergent gameplay and while not a new concept it is not yet widespread.
Which brings me to the recently released Scribblenauts. Scribblenauts is an action/puzzle hybrid developed by 5th Cell for the Nintendo DS. The gameplay is essential simple, the main character has to get from one end of the level to the other and there are many obstacles in their way. To get past these obstacles the player types in a word and that animal, person, object, or anything else in summoned into the world. The dictionary for the game is mind blowingly deep. Words like god, Cthulu, time machine, halberd, and ewe have no problem being generated and each of these things have their own behaviors and properties. Search youtube for Scribblenauts videos and you will see a T-Rex riding, shotgun wielding main character mow down zombies while the Krakken flops around on dry land. The game probably would have been fun with a large set list of items but the well thought out use of emergent gameplay turns it into something you can sink a potentially limitless number of hours into and ensures that no one’s gameplay experience is identical.
As hardware becomes more powerful we will start seeing more emergent gameplay as one of the most taxing things a game can do is simulate reality. Soon the age old cry that video games rob children of their imagination can finally be put to rest.