It is an unfortunate truth that despite the great effort the designers put into this game, sometimes there are problems with certain cards and certain quests, and sometimes there are things which are flat out broken and can be exploited. And when I say broken I don’t mean broken in the sense that you might say for instance, “Outlands are totally broken and overpowered,” I mean broken in the sense that certain quests under certain conditions stop functioning as intended or significant parts of them get trivialised.
Now while there may be some potential earlier examples, Shadow and Flame is one of the most egregious cases and also one of the most obvious. For starters obviously there’s a massive difference between taking any random deck against the quest and building decks specifically for it, since if you build specifically for it you can throw in all your high threat heroes and a load of Secrecy cards as well for a very impressively powerful deck. But it goes even further than that. The whole challenge of the quest comes down to fighting the Balrog – soaking up its constant attacks while still building up enough attack power to kill it at the end. So anything which diminishes that combat load has a massive impact – and there are two ways of significantly diminishing that load – cancelling the attacks or lowering your threat back to 0 so it won’t even try to attack you.
Break the First
The classic means of consistently doing the first is of course the infamous Hama-lock. If you’re not familiar with the concept, the idea is to use Hama’s ability to repeatedly recycle the same copy of Feint so Durin’s Bane never actually attacks. In a mono-Tactics deck Thicket of Spears also works of course. This approach was so effective it led to the errata on Feint and Thicket of Spears, such that they only prevent the enemy attacking one player rather than preventing it attacking full stop. Now it’s less crazy since it only keeps one player safe, but if you’re playing solo and quickly draw a Feint it still works just fine (Thicket of Spears of course would require you to be mono-Tactics, which would leave you in a dubious position with regards to questing successfully – on the other hand not being mono-Tactics means you can possibly have better card draw to find that Feint faster).
Other approaches could involve loading up on attack cancelling effects like Feint, Out of Sight, Hobbit Sense in a Hobbit deck, etc. This is much less reliable however, though it has become more feasible as the card pool has grown and given us more attack cancellation effects for greater consistency. And in mono-sphere we can have some recycling via the Record attachments (well, we could use them outside of mono-sphere, but it’d be more expensive then).
Break the Second
The second method, dropping your threat back to 0 so Durin’s Bane is no longer considered to be engaged with you, didn’t have a means at the time of release of being done that reliably. If you drew a Galadhrim’s Greeting or Elrond’s Counsel at a relevant point that would certainly work, but you can’t expect to keep doing it over and over again. The only repeatable threat reduction at the time was Dwalin, and while there are enough orcs in the quest for it to be plausible, you’d need to use a Quick Strike to have Dwalin kill the orc and drop your threat before enemy attacks for it to actually work.
Now with the Map of Earnil, this becomes a bit more of a reliable approach, since you can get extra uses out of your threat reduction events, but something entirely repeatable would still be better, and we have two options in this regard.
Immediately after Shadow and Flame, the first Hobbit saga expansion gave us Nori, who even post errata can drop your threat by 1 every round consistently enough, so long as you have a steady stream of Dwarf allies to play (and play them one at a time since you can’t put your threat into negatives). This isn’t perfectly reliable since it does depend on you having those Dwarf allies, but you should be able to stuff a deck full enough of Dwarves that it’ll be fairly consistent.
And of course more recently we’ve received hero Galadriel, who can drop your threat by 1 every round with no additional support required. At which point so long as you keep questing successfully and don’t get screwed over by the two copies of Massing in the Deep (Doomed 1), you can get through the quest with as few as two Balrog attacks – one when you advance to stage 3 and one when you deliberately delay using Galadriel so you can attack the Balrog in turn.
Between these two, Nori doesn’t have so much of a problem with Massing in the Deep, because you can just play two Dwarves the following round, whereas Galadriel would need to have some other sort of threat reduction to deal with that. On the other hand it’s entirely plausible to get through a play of this quest without seeing Massing in the Deep at all, and Galadriel isn’t dependent on anything else, which gives you free reign over what other cards you want in your deck and is perfectly consistent since she’s on the table from the start. The additional card draw also comes in handy, of course.
An interesting point to note is that both these two means of breaking the quest work just as well in the Nightmare version – Nightmare Durin’s Bane is the same as regular so repeatedly Feinting it is just as effective, and there’s nothing stopping you lowering your threat either (nor indeed are there any more cards which would forcibly raise your threat as I recall). This is in contrast to some Nightmare decks where the designers very specifically made an effort to counteract some of the most effective strategies for messing with the original version of the quest.
When playing Shadow and Flame three player (quite a while ago now), we decided to try and break the quest as thoroughly as possible, using a Hama deck, a Nori deck and a Galadriel deck. This was the result: