MUDs like, uh, most, uh, most games these days really, uh, are not a scripted series of events at all, um, but really a system that is built to simulate, uh, a world. So, uh, I think that was a very important thing about, um, and probably, again, one of the sort of important, uh, choices that were made by Bartle and Trubshaw when they built MUD and some of the other early, uh, you know, similar games, um, was to build kind of sandbox open worlds to some degree. MUD actually was more or less on rails in some respects in so far as there were things you did and, you know, there was repetition and a kind of grind to the game as there are in most MMOs. But, uh, the idea of the game and the thought that went into it and the sort of nuances and the later evolutions of Bartle's work were very much about creating complex systems where things made sense. So, if you took something, you took and dropped it in a hole and it would fall through the hole and end up somewhere below. And logical causal connection -- if you pick something up it wouldn't be there for the next person; if you put something down, someone else could find it. Um, and so on. So, that sense of it being a real world with a reality that obeys not necessarily the laws of physics, uh, you know, that people can construct a mental model of that allows them to feel that they are part of that world and it makes sense to them and they understand the way it's organized. Um, and I think that's a tremendously important part of the medium because it allows the player to project themselves into the space to make sense of it and to play the game. Really they're playing the game in their mental model of what they're experiencing and this is why I think MUDs are a kind of still a tremendously interesting medium because I don't think the text actually matters, versus incredibly high production value graphics. I think actually the game that people are playing is generally being played, uh, in the back of their brains, not on the screen. Um, and if anything, I think sometimes the fidelity of the graphics can, uh, dilute the, uh, compelling nature of the player's own mental model.