Ok, to refresh, I posited that the three main models of adventure motivation are Procedural (sequence of scenes or reverts towards a dramatic or appropriate conclusion), Goal-driven (moderately open play with a goal providing overall direction) and Situational (Where the characters are put in a situation which will evolve based on their play).
I present these as a triad rather than a sequence because it is not hard for these to bleed into one another, and in reality, it is rare for a game to move purely to one of these points, and rarer still for it to stay there. Instead, actual play moved towards the spaces in between these points, and those can be described in broad terms.
Between Situation and Procedure, we have Exploration play, which it might more accurately call progression. The model is simple: When play begins, the players are in a particular place or state (such as the small town near the low level dungeon), and as the game progresses, the range of places available to to the players expands. This is probably most commonly seen in video games, but it’s also a common part of D&D and D&D style adventures. The 4e model of moving from the world to the inner planes and on to the outer plains is also a good example of this. The procedural element revolves around the progression from zone to zone, as it were, but it’s still largely situational because those “zones” are large may have a lot of scope for play within them.
The Quest is a combination of Procedure and Goal based play: it’s got a clear goal (the object of the quest) but there’s a chain of steps to go through to get to that point – to kill the dragon, you have to get the sword, to get the sword you have to find the tomb, to find the tomb you need to brave the archives and so on.
Finally, between Goal and Situation, you have Sandbox style play. There’s an ultimate objective in the form of the goal, but there’s no real limit on how the characters are going to proceed nor at what pace.
So, that puts us up to six models, but the important thing to note is that NONE of these models automatically translate into a good or bad game, nor even faintly trend that way. Each one of those models can be used to build a very good adventure or a truly abysmal one. I’m not just speaking in terms of personal taste – I mean really, genuinely terrible adventures.
That said, these models _can_ be useful when it comes time to talk with players about the game. If you can talk about the models directly then that’s probably easiest, but even if you don’t speak in explicit terms, it’s something to keep in mind as they talk about the sort of game they expect.