Both last year and this year at Origins we played True Dungeon adventures (one each year). I don't want to spoil either of the adventures we played (which they continue to offer), so I'll speak here in generalities.
True Dungeon is something like D&D adapted for physical sets. An adventure consists of a story played out in a series of seven rooms. You play one of a dozen or so character classes and each has some special rules and abilities. Spellcasters usually have to memorize things (cleric: identify this prayer bead to successfully cast your spell, etc). To disarm traps, rogues have to manipulate a gadget that is akin to playing the old board game Operation (move a pointer through a maze without touching any walls). Combat is done on shuffleboards; monster hit areas, including vulnerabilities, are drawn on one end, and you slide disks from the other to attack. (I'm not sure if monster damage is pre-determined or randomized; I didn't get a good look at what the GMs were doing.)
Before the session starts, the players get together to choose classes (no duplication allowed) and equip characters. Equipment comes in the form of tokens; each time you play you get a bag of ten (most common, a couple uncommon, one rare -- this should sound familiar to anyone who's played collectible card games like Magic). Naturally, you can buy specific tokens from them. Both times we played, the assortment we got for that session was not, by itself, particularly useful (I don't think my bag included a weapon, for instance), so you're relying on the experienced players who show up with their vast collections who can say "sure, you can borrow this sword" or "hey cleric, here are some healing scrolls, just in case". At the end of an adventure you get a few more random tokens. "Equipping" consists of laying out the tokens you're going to use (armor, weapons, cloaks, rings, etc) for a GM who records your final stats on a sheet that is carried through the adventure and given to each GM. You can then put most of them away, aside from weapons and any expendables you want to have on hand.
The game can accommodate up to ten players in a group. Last year we had only three, which did not work well. In retrospect we should have asked if the next timeslot's group was also light and, if so, could we combine. This year when we signed up we looked for a timeslot that already had some people and ended up with eight, which worked much better.
An example of "worked better": some rooms have a subtle clue that, once you notice it, helps you in solving whatever that room's problem is. With more people there's more likely to be someone who notices subtle clues. Of course, the flip side is that with more players you can end up in "too many cooks" territory when solving puzzles, but our eight-person group worked pretty well together.
They bill this as a two-hour game, but it's actually both more and less. Each room has a time limit of 12 minutes, so the worst-case scenario for the actual playing is 84 minutes. (That might even be typical, as even if you finish quickly, you've got to wait for the group ahead of you to clear the next room.) But then there's the time you spend equipping; I didn't notice last year, but this year we entered our dungeon at least 45 minutes after our nominal start time. And they ask you to show up 20 minutes early. So while it's listed as a two-hour game, when scheduling at a convention, use a three-hour timeslot.
The game is dark. Rooms are generally lit in green, and when you've used half your time it switches to red. (That warning is a nice touch.) Players are issued small flashlights; I think they intend for you to clip them onto your character card (which is hanging around your neck), but since I needed to be able to read part of my card (the spell list) I ended up tying the flashlight around my wrist. I had a pile of one-use magic items in my pockets that I could in principle use in combat when needed, but as a practical matter, there was no real way to dig through them in that lighting. Anticipating that, I distributed tokens among different pockets in my jeans, but even so, I mostly couldn't use them. I've seen pictures of players with sashes full of tokens (not sure how they're attached), presumably to solve that problem. Last year our third player, who came in costume, had a big shield full of tokens. I've been thinking that something like a triptych might work better for me -- easier to use than a sash and easier to pack than a shield.
Last year I played a monk. The monk doesn't use much equipment but fights two-handed. Well, sort of: you get two disks in each round of combat instead of one, but you launch both with the same hand, one immediately after the other. (The second one has to be underway before the first one stops moving.) That was...ok, but I don't think I did a lot of damage, and actual two-handed combat (with weapons) sounds like a better idea to me (I'm probably about as good with either hand). That's the ranger's ability, and ranger was my second choice for this year.
This year I played a bard. I wrote about that a little before the convention, in particular the "bardsong" ability. They describe bards as jacks of all trades; a bard can fight, has some spells (D&D: like sorcerors, not like wizards), can use lore knowledge to get hints, and can sing during combat to give bonuses to other players. It turns out a bard cannot sing while fighting, even if a bard player can demonstrate the ability to do just that, absent a magic item that enables it. So I had weapons in my pocket but I ended up giving bonuses (and casting some spells) instead of fighting myself. I ended up feeling a little too much like a back-end support character without primary contributions, so next time I'll try something else.
We had, I think, three combats (maybe four? I think three). I sang a variety of medieval and renaissance songs not in English, to minimize distraction. (In one fight with a sort of demonic character, I switched to singing psalms. I don't think anyone noticed.) But because the other players and GM needed to communicate about hits and damage, I ended up standing back and singing quietly. Meh on the bardsong ability; I wasn't able to make it sufficiently fun.
I invoked "lore" two or three times. The way this is implemented is that, before the game starts, you're given a set of labeled glyphs to memorize. When you use the ability, the GM shows you a glyph and if you can name it, you get the clue. I thought there would be a lot fewer of these! For some reason, in advance I thought there were 14; there were actually 24 and many of them were not at all intuitive. (I wonder if they randomize the labels for each adventure, or if playing the same class repeatedly lets you build up knowledge.) Nonetheless, I got one or two right immediately, and in one room I initially said I didn't know and then 30 seconds later said "wait, that's X" and the GM gave it to me.
The spells I had were interesting but not optimal for this adventure. In particular, the bard's highest-level spell does mass damage, and we never faced groups of opponents. Last year there was one group.
Half or more of the adventure was puzzles. This year's puzzles were well-done. (Last year's were a mixed bag, though we also had fewer players and thus fewer brains to tap into.) Two of this year's were especially fun to solve and made good use of props and actors. (I think those facts are related.) In one room, the GM said that since we didn't have a rogue, our bard could try the rogue gadget to get a clue. This confirmed my initial impression of the rogue gadget. :-) I gave it a good try, but...not my strong suit. Also, it takes enough time and focus that you miss out on what else is going on in the room at the time, so I suspect playing a rogue would feel somewhat isolating.
The sets were well-done, including the animated big-ass monster in our last room. Another monster was represented by an actor. Last year I think the GMs (each room has one) were also actors; this year there were GMs who were not actors (and not in costume). Of course most of the players aren't in costume either (some are), but it's something I noticed anyway.
I think the GMs had some latitude to make tweaks on the fly. This makes sense; nobody enjoys an adventure where half the party gets killed before the end, after all, and people are paying (substantially) to play. Keeping it challenging but achievable with highly varied player abilities and group sizes seems hard, especially when each GM only sees a group in one room. I wonder if they're issued any heuristics or if it comes down to individual GMs winging it. (An example: in one of our rooms I bumped into a bucket on the floor and looked inside. It seemed empty, but the GM told me it contained holy water and the person who'd been lobbing flasks of same at an undead monster could refill them instead of turning in the tokens. Actually, the GM told me, there was a leak in the ceiling and that's why the bucket was there.)
I had fun. I'm still looking for the character class(es) that will be the most fun for me, but I have ideas. It's expensive enough that I'm not going to play a lot, so equipping is likely to continue to depend on teammate bounty. Which is fine; the hard-core players seemed ready to equip others. If our tokens were organized we might have been able to make some trades, but when what you've got is a bag of misc, it doesn't seem practical.