The Friday game group I'm in has started playing Legend of the Five Rings and specifically started out playing an adventure designed for a purpose - to introduce the game. I'm not sure if this came with the game or was a supplement, and I'm not sure how much is in the material and how much is coming from the GM, but it is a very good introduction to the system. The players choose between the available Clans and have to compete/cooperate in a competition called the Topaz Championship. The various competitions staged allow the GM to gradually introduce game mechanics as well as setting information and tone in a way that doesn't overwhelm the players (us!). In L5R it's hard enough to get a handle on the clans, the setting history, and the names of people and things, so this really helps - even though most of us have played many game systems. I find it fascinating how this was done and I think it's a good idea for any system to try to put out some sort of intro adventure - even if the game is pretty rules light. The effect of using this adventure to introduce the game and setting has been to really fire me up to play this now that our characters have passed our challenges and are ready to have our gempukku ceremonies and become samurai. We're gonna kick ass and take names and really clean up this town - just you wait and see.
I found this adventure was different than what's usually given as an introductory adventure - the very basic "oh you read the scroll - you will be a magic-user, you picked up the sword - you will be the fighter". It was the type of adventure geared towards players who may or may not know how to play in a particular setting or with specific rules, but do not need to be told how to roll a d4 or to "picture in their heads a character from a storybook". I'm sure there's a need for that other type of introduction to RP gaming - the very basic concepts - however I think most of the time players need setting and system information but not an introduction to the hobby. You only need to learn that once, and I believe most new gamers will be learning how to play with other established players, and not from a solo adventure in a rulebook. No-one is likely to pick up and play Beacon cold if they haven't played D&D or been introduced to it via a game group anyway. I think I am really noticing the difference here because I've been reading Adventures in OZ and the Adventurer Conqueror King PDFs I recently picked up on RPGnow and they spend a lot of page on those real basics. Maybe L5R does as well but I didn't read that part of the book - just dived right in. Its one thing to do this in a 600 page rule book, but in a smaller game or PDF maybe that space could be better used.
Just from our small game group and from playing with my kids, I've found that there is little or no practical difference in the ability of our
least experienced player to deal with a new game system than the more
experienced ones. Any concepts that might be unfamiliar, like
initiative order or attack modifiers, or saving throws is pretty quickly transmitted
through play. We have a player in our group who has literally only ever played the
games we've run, Beacon, Trail of Cthulhu and this L5R game, and she
seems to be just as able as the veterans to pick up the mechanics either
by emulation or by intuition. I don't think a paragraph on how to read
a d4 would have been useful to her.
I think you can guess where I'm going with this. I really liked the L5R adventure and I'm much more interested in writing up a sample adventure to be used with Beacon than I am with beefing up the explanatory text in the rules because I think that there's more bang for the buck to be had this way. I am torn however because the way I run my game is to basically set up a skeleton of a sandbox and then dump in adventure sites and situations from existing modules. On a side note I've been a bit antsy because I really wanted to write up some posts about the cool adventures I found and used for the play test, but I don't want to ruin the campaign I was running by posting links and discussing the material when there was a chance the players would see it. I don't distrust them, and I edit things a lot during a session, but I think it could certainly spoil some of the surprises.
So I can't see doing a simple dungeon crawl or mega-dungeon supplement for this purpose. I would like to design a couple smaller installations (cause it's fun!), but really there are so many good ones already I don't see a lot of value in mapping out yet more shrines, cities and abandoned tombs. What I can see value in however is some sort of area adventure guide that detailed some setting and NPC information, encounter tables, and contained liberal hooks designed to introduce concepts to players and GMs. By doing this as a sort of gazetteer instead of an adventure, I could even call out to the modules I used to populate specific sites with notes as to how I used them. I could even include some small notes on why I chose those adventures for those areas. I think that that might be even more useful than a prepared adventure.