I'm not saying it couldn't be done. I'm just saying it's very unlikely that a convention group with just four hours could complete this without some additional foreknowledge or help, and this estimate is based on the experiences of our actual group play.
To note, our group did successfully beat the dungeon, but not on the first attempt, ...nor even the second. We started about seven or eight pm. I quit by ten, after losing the wizard in our second run through, and the bulk of the rest of the group played through until they completed the Tomb of Horrors and quit around three or four a.m. Many of our weekends in high school went that way. It took like five or six attempts before they finally succeeded and it was a real bloodbath.
I remember where the Canary came from now. In ToH the Canary in a Cage came with one of the Pre-gen characters or as an additional equipment option the players could add in the pre-dungeon outfitting phase of the adventure. I do remember one player taking this option now and carrying a canary in a cage into the Tomb of Horrors. He died. The Canary died. We did have a discussion about the canary though during the game, after the first couple run throughs that went something like this;
Me: "Why are you bringing a canary in a cage into this dungeon?"
Tom: "Well, you know, it's like in a mine, if there's no air, or poisonous gas, the canary will die first, and we'll get some warning that we need to act."
Me: "Really??? just what exactly do you plan on doing if the canary dies? You have just a few rounds before you too will suffocate, or die a horrible death because of the poison."
Tom: "We can leave, and go back out the way we came in."
Me: (Thinking about one way doors and slide traps) "uuuhh-huh..."
Tom: "And the cleric can heal us..."
Me: "OK, what spells can help? Ahh remove poision! But how is the cleric going to know if you need to have poison removed, or if you are instead out of air and suffocating? ...And how many spells or scrolls like this is the cleric going to need to keep the whole party alive? You think the cleric is going to have time to save everybody, or is he going to use his spells to save himself?"
Tom: " I dunno..."
I'm sure Gary and Frank and company laughed their a$$es off when they walked into the convention center gaming hall and saw all these players with big tough fighters, Fear inducing thieves, and awesome wizards, who were daintily traipsing through the dungeon hauling canaries in cages. This goes right back to the Monty Haul "Let's make a Deal" theme, where people would show up in the most ridiculous of costumes in order to wow Monty and persuade him to favor them. The same with the players and GM ...in game with ToH. Yay!
If it helps any, our gaming group didn't like to think of ourselves in those terms. Instead of Canaries in a Coal Mine, we envisioned ourselves to be a lot more like Conan, Subotai, and Valeria, when they stole into the underground stronghold of Thulsa Doom to kidnap the Princess in Conan the Barbarian. We go in fast using stealth and camouflage, dodge or disarm the traps, kill anything that needs to be killed, and get out fast with the treasure/loot, and with the least amount of alarm, or fuss.
Now Hussar is right, It's a very good dungeon, but not in the way one would immediately expect, or guess. Here's what actual effect this play through had on me;
1) Other than B1 (Which was an exceptionally well designed dungeon) I had not played in any TSR Dungeon. We had taken the Holmes blue book to heart, and had happily crafted our own dungeons and story lines for years before and were already well versed in fiendish Dungeon design by the time ToH even came out. Other than B1, I never bought a TSR dungeon module, and didn't buy another dungeon module until after 2000 when WOTC released Forge of Fury. And that was only after I had a chance to examine an already opened copy of Forge of Fury.
TSR used to shrink wrap all of their dungeon and dragon modules so I couldn't inspect them for quality, This also put me off from buying any more modules, specifically becuase of our experiences with ToH. I did play in one other campaign where my friend Tom ran the B4 The Lost City adventure, right after it was released in 1982. It was also very good, and I enjoyed it even though I lost two of the five characters that I played during that adventure.
2) When we went back to making our own dungeons, I always made sure to include at least two available methods or techniques any player could use to disarm any trap, because I wanted to avoid having my dungeon labeled a "Railroad" which was a term we first heard not too long after the release of Tomb of Horrors.
3) Whenever somebody did use the term "Railroad" to describe an adventure or game. I always though first of Tomb of Horrors and that inexperienced GM, and that evening where I lost my best wizard in a sadistic deathtrap where I felt, ...despite my best efforts, there would have been no chance to win. Most games, and adventures that earned the label railroad were ones that I personally avoided, and to this day avoid, because it reveals a fatal flaw in the inherent design that is not properly being addressed by the game designer.
It's not a matter of game balance, as an adventure can be unbalanced and tilted in the favor of players, or tilted against them. A really good game should be neither, and it should be up to the players to eke out a victory against a series of challenges, some more difficult, and some less difficult, but no challenge should be so difficult that it cannot be overcome. Any challenge like that and it is no longer a game.
