Rand: It would be a great study in psychology to see differences in the two in the way they are played. We actually tried to accomplish that in Riven. We discovered from Myst that there were two people who liked to play our games. There was the gamesplayers who liked the puzzle challenge. They were looking for that reward, that 'yeah!', that feeling you get when you complete the puzzle.

And then there were the explorers. The people who didn't normally play games, who got onto Myst island and looked around and thought, 'my goodness, isn't this interesting' and may have got sucked in enough that they wanted to continue on. Our point in Riven was - let's give the explorers a little more area to explore, a little more opportunity to get sucked into the story and want to continue before we start putting the hindrances there. But, towards the end, we wanted to make the puzzles even more challenging so that the gamers are very satisfied as well. In the end, it was all an experiment, I don't know if we accomplished it. I mean, you still hit the wall, you just have a little bit more room to wander around.

But now, I think it interesting you said you hit the wall sooner in Riven than in Myst, because we were thinking just the opposite. In Myst all you had to explore was Myst island and before you got off there was a substantial amount of puzzle you had to finally put together to get off of that. Whereas Riven has little puzzles to open up new areas.

Gus: Sure. In Myst you are limited early on, but because there is a limited space and limited amount of significant objects, you do focus on them and realise they are the key to progress. In Riven, you have such a wide area early on its different to focus on what's important. Everything is so rich - when you go down to the beach, for example, when the animals go off whether they are there for show or lead to something else.

Rand: Yeah. I think if there's something I'd like to tweak in Riven that's it. I think just by chance in Myst, not by incredible design on our part, Myst was very compartmentalised, and that worked incredibly well, because you knew that to solve this age, all you needed were the things on this age. Riven was an experiment in different things - let's not so compartmentalise it. We did to an extent, obviously there are islands which keep things separated but we also put in a few things to mix it up a bit. I don't know if that's good or not.

Gus: I think it is. It works a lot better because you reach a point where you're not getting anywhere, that's what gives you the time to sit back and think about how the story parts relate. That's how my friend and I began to talk about the religious element we discussed earlier. We began linking ideas like the fish-summoning room with its use an educational icon etc. You can't do that in Myst because each island is distinct.

Rand: And we didn't do it as well in Myst. Our storytelling in Myst is not anywhere near the level it is in Riven. We didn't build enough story in there. It's a little more eclectic; there are just scattered things, where in Riven we thought purposefully we had to create a story to support and wrap around it.

Josh: One of the things I started to appreciate in Riven when we were first designing it: we knew we wanted to give the player a bigger area to go through and we wanted to change the way the player played the game. I was excited by the idea of players going to these new areas to explore, like you said, but that there was also the opportunity to immediately go somewhere else. So it's a choice - do I leave this place or do I stay and figure it out - even down to the lagoon with the creatures on the rock. We built puzzles so that you had to slow down and take your time as opposed to just running all over the place and getting to all the puzzles. The puzzles were integrated a lot better.

Gus: How difficult is it to work out how long it will take for the average player to 'get' something?

Rand: Incredibly. At the very beginning, before we had done any computer work at all, after the initial design by the four of us, we brought in six or seven people, went to a room, closed the door, ordered pizza and played the game in a roleplay way. We described the pictures, described the situations and said 'now you see this, what do you want to do?' and went through the entire game in that way. And that gives you a little bit of a clue on what people are thinking. You're able to tweak things at that point.

In addition we were able to little bits and pieces in that allowed us to give more or less information away. The journals are a good example. You are always able to change a little bit of information you give in the journal to help or hinder the player, depending on your testing later. But you don't have a lot of control over that. To some extent, you have no idea right up to the end of how long it will take people to play this game.

Gus: The journals. That's quite interesting, it appears to me you appear to take a more difficult path with them in Riven. You take a greater risk, in that in Myst the journals are all available early on, so you're not taking the risk of someone getting completely stuck, whereas in Riven I have only found two books, so all the puzzle-solving is done purely from the player's vision of the world, and not by poring through some book until they get to a diagram.

Rand: That's right. There is some of that, little things, but that's largely because, I think, we were able to integrate the puzzles better in Riven. A good example is the boiler by the lake. The fact is that this boiler is a puzzle, and the plain fact is that a gameplayer can gloss over that fact and just see it as a puzzle, but we were very intent on giving it a purpose. A puzzle should be there for a reason. You can't always do that, sometimes you have to use artistic license, but we did try very hard so that we didn't have an arbitrary thing in there with no reason to be there.

Gus: Taking the boiler as an example, I think I've worked out the purpose, which hasn't been of use. There's been a puzzle involved with it, in that the boiler is a route to another place-

Rand: That's right.

Gus: The purpose is something different, to do with the water and the lifeform-

Rand: Not exactly. Remember how you got to the boiler and the equipment next to boiler-

Gus: Sorry, it's used to create the books.

Rand: Yeah.

Josh: Don't give too much away-

Rand: No, he's figured it out. And go back to fact you took a train in that little lumber car from the area where all the trees had been cut down. Where the logs had been chopped up he's attempting to make paper.

Gus: Actually, yes. That whole area is for the production of books, but we also thought, with what we read about the lifeform in the water and how it dies when heated, we thought there might be a secondary purpose in heating it.