I build a bonfire ever week in our backyard for family cookouts during the fall, gathering fuel from our woods. Even with lighter fluid (which is a last resort), the day after a rain is still a PITA. Even using some wood I've keep dry...nothing seems willing to burn---just smolder. The turning of liquid water into steam sucks energy out of the system. Even if eventual success is achieved, it's a long, drawn-out smokey mess. Winter, in comparison, is very dry. So, this thinking does not really match my experience.
Also...your group feels empowered to veto whatever explict game mechanic doesn't sit well with them?
What I meant was that they would not accept that wet wood can't be made to burn, and would step up their efforts to change the default assumptions of the module, eventually ending up with something that would work.
Also, the DM absolutely has the right to veto mechanics that don't make sense in the circumstances.
Green wood harvested from the outdoors in winter is not only wet, because it has not been cured, but is frozen, so you have to melt it before you can dry it. The key is to light a small fire with thin kindling first; the wood is thin enough that it dries quickly as you light it and goes right away. (The kindling can be made by splitting slivers off of larger pieces of wood.) You add thicker kindling to that fire, and the small fire dries the kindling to that it can light. Once the heavier kindling is lit, it burns hot enough and long enough to light even green wood, as long as it is split. A fire of split wood could easily dry out and light a wet wooden wall that it was stacked against.
I'm a bit lazy, so I usually build it all in one stack, larger pieces on top of small pieces, with a couple of larger bits of wood on the bottom which I build the pile on so you get air circulation underneath. Using no accelerant, but a bunch of balled up newspaper, I can usually get a stable fire lit indoors (that is, the split logs are burning reliably) in about ten minutes. Outdoors can take a bit longer, with wind blowing out small fires, etc., but I would say 20 minutes, max, as long as it is not actively raining. I would guess that sacrificing a torch, which has a wick and (in D&D, not RL) burns for an hour would easily replace the paper even in less ideal conditions.
If you are using supersaturated, rotting deadfall that was half buried in the ground you might have a problem. But you have to assume the place was built with green logs, not rotting logs, or it would collapse.
, doing all of that in hostile conditions isn't not work
, and if the PCs take the time to assemble the materials, make the kindling, and get the fire going then I'm going to let it play out however it wants without punishing the players for it. The PCs probably don't know about the secret door in the great hall at this point, so it is possible that a bunch of drunk giants in a burning hall where the main doors are barred could find their way to the dungeon just like the module says. Or the fire could be discovered early, and the giants could form a bucket brigade trying to deal with it, which could also help the PCs. Whatever, it's my job to adjudicate whatever mess the players decide to make, not nerf their attempts to draw outside the lines.
I view the rules as an aid to adjudication, to be used as long as the assumptions for which they were designed exist, and to be ignored when said assumptions are no longer valid. I'm not running this as a tournament module so colouring outside the lines is allowed and bizarre contrivances are not necessary. I assume Gygax' admonition regarding the lighting of a fire applied to the assumption that players were not taking significant efforts to start one - in other words, that they were just holding a torch to the logs on the assumption that it would go up in flames (like anyone whose experiences with lighting fires come from watching TV and movies). If the players decide to kick it up a notch, and accept the consequences, then I'm going to let them.
Keep in mind, there are still interesting things coming out of this. If the players light the fire outside of the building, it may well be discovered before it gets too far in, is probably easier to put out (the exterior wood is setter), and they have given themselves away. If they light it inside the building, they either have to stay inside a burning building to make sure it keeps burning, killing anyone who finds them to make sure it is not discovered; or abandon the fire and hope for the best. Then, once it is well underway, they have to find their way out amidst chaos, with giants very active and running everywhere. Every different location where they might build the fire carries potentially different consequences. Not being able to light the fire is the least interesting of them.
, G1 does not contain an admonition to gather information, that comes in the later modules. The players are to "punish
the miscreant giants ... deliver a sharp check, deal a lesson to the clan of hill giants nearby." They are only to follow clues if they find them, they have not been charged to actively seek them out. This is an assault mission, not a recon mission.
Also, I assume Gygax included the mechanic because either someone attempted it at the table, or he expected that someone would. Players do dumb things all the time.