In no particular order. Design goals, best practices, aesthetic principles. Some things I find myself striving toward, talking about, doing. It's categorically untrue that I always do all of these things, of course. But maybe you can see what I'm reaching toward.
Feel free to add, elaborate, or dispute in comments.
Content is a reward. Make sure the content you provide is worth the effort you're rewarding. Even an autoresponder should be worth the time it takes to read it.
Never, never let effort go unrewarded, even if the effort isn't what you expected or wanted.
That said, don't excessively reward players heading in the wrong direction -- the volume with which you respond is an indication as to whether they're barking up the wrong tree.
Each discrete piece of your game should be independently entertaining in its own right, even if the player never sees another piece of it.
If you want to make a game for a mass audience, there should be something for every level of involvement, if possible, and for as many kinds of players as you can manage: explorers, achievers, socializers, killers; more than just spectators, speculators and solvers. Read up on Dr. Bartle.
Try to make an experience that would make sense even to a single player who is too shy or otherwise unmotivated to find or join a community.
Be aware of trolls. Consider interactive elements of your design from the perspective of somebody who has the most fun when defecating into somebody else's swimming pool.
Reference new content streams from within a known-in-game source as soon after discovery as possible. Once firmly established, this habit both supports the players' effort by acknowledging it and helps to prevent gamejacking.
Again, for a large-scale game, whenever possible, keep all communication in the open. Do as little as possible through private IM and email. This scales much better and will save you time and headaches.
Consider structure. Completely open-ended games can lose players who miss a road sign and get lost. Structure can mean a guide through the experience (often a cute brunette girl). It can mean a central website acting as a story clearinghouse. Just make sure players know where to look, and when, rather than guessing.
Make sure it's obvious to your players what their current goal is. Uncertainty isn't that much fun.
Use your structure to provide clear calls to action from time to time. It's helpful to get everybody on the same page now and again.
Provide rolling recaps. This serves two purposes: It allows existing players to attend to an urgency (vacation, term paper, conference) without risk of losing the thread of the story. It also allows new players a simple way to jump in, even late in the game.
Value your players' time and attention as much as they do. Don't release a lot of content solely for the sake of having a lot of content; don't create a lot of puzzles solely for the sake of having a lot of puzzles. It's surprisingly easy to overwhelm players with more information than they can process at once.
Manage expectations carefully. Don't commit yourself to a volume of content you can't realistically do, like live IM around the clock, or fifteen updates every single day.
The players will generally care less about plausibility than you do. Still, you need to put in the footwork on the motivations and actions of your cast. Make sure you understand how all of the parts of your game fit together, or the gears will grind instead of spinning.
Never let realism get in the way of fun.
...don't excessively reward players heading in the wrong direction -- the volume with which you respond is an indication as to whether they're barking up the wrong tree.
Unless you're willing to, if we extend the metaphor a bit further, grow a new tree. ;)
Read up on Dr. Bartle.
I've recently been reading Designing Virtual Worlds by Richard Bartle. I've been impressed with it so far; very well researched, accessible but insightful writing.
Never let realism get in the way of fun.
Haha! That applies to a lot of things. I feel like I should write that on a post-it and put it on my monitor. :)
I've always thought of it as...You can get away with pretty much anything, as long as you make the effort to sell it to the players. (Or readers, or viewers...)
Posted by: John Evans | March 31, 2009 at 22:55
The new tree bit is a nice thought, when it's possible; but if your the wheels on your plot are packed in very tightly, there will of necessity be points where you need the players to zag instead of zig, or you won't move forward anymore. It's highly situational, I suppose.
The realistic != fun lesson is one I learned many years ago when I had friends designing paper RPGs for maximum realism. It turns out playing an RPG where you die of bleeding out or of shock the first time somebody gets a good shot at you with a crossbow... not actually very fun. Go figure!
This is also, of course, why there are no lavatories in Norrath.
Posted by: Andrea | March 31, 2009 at 23:18
This is really, really excellent information and should be required reading for anyone looking to create any sort of interactive experience. Kudos!
Posted by: Addlepated | March 31, 2009 at 23:28
I think its hugely important that players know what they are supposed to be doing. The majority don't understand the conventions of ARGs - that the people and places that you encounter in passive viewing/play can be found and interacted with across the web. We did a great focus group last night with some late teens and they explicitly said (several times) 'I would have benefited from instructions'.
Posted by: Jo | April 01, 2009 at 07:37
Aw, thanks, Addle. :)
Jo, I think there's definitely a value in providing clearer instructions, particularly for younger players, and particularly for players who haven't done an ARG or anything like it.
It's a tussle between allowing depth of immersion and keeping the magic circle intact, vs. making sure people know what the heck they're supposed to be doing. But I think as a group, ARG designers usually err on the side of mysterious... the whole curtain/TINAG thing. I wonder if we'd grow audience faster if we erred on the side of more directly telling players what to do.
Posted by: Andrea | April 01, 2009 at 08:40
Yep - agreed. I think if you want to attract a broad mainstream audience you have to sacrifice the mystery at the point/s of entry. Having said that, once they're in and they understand the principles I think players can easily suspend their disbelief. In the same way that you understand a movie is not real, because you walk into the cinema, you can still immerse yourself in it. Once past an instruction screen, in an ARG, you're free to enjoy the game.
Posted by: Jo | April 01, 2009 at 11:27
*nodnod* Of course we agree on this, Jo. ^_^ Send out a press release! Run ads and flyers!
This is especially going to be necessary for the brave souls who will do the next round of subscription games. I firmly believe that will be a winning model, as soon as there's sufficient public awareness of the existence and playing methods for immersive games.
Posted by: Andrea | April 02, 2009 at 18:07