From an older-school RQ perspective (haven't run any dungeon crawls in MRQ/RQ6):
Traps can be deadly - pits aren't too bad, but crossbows triggered by tripwires can kill, or at least badly injure
Generally being outnumbered is bad, being heavily outnumbered is almost fatal, in those situations it is best to manoeuvre yourself into a better position
Lots of small encounters can wear down a powerful party, just by reducing fatigue, magic points, hot points and using divine spells.
Bound spirits and ghosts can be especially troublesome, particularly for PCs who do not have good spirit combat spells or a high POW

PCs who encounter enemy shrines will try to desecrate the shrine, which will bring on retribution from the shrine guardians.

Powerful denizens will use Warding to cover entrances - A Warding 4 can do 4D3 damage to a location and can knock down many PCs.

Acid is always funny, especially against Rune Lords who have just got a shiny piece of iron armour, or a shiny iron sword. Gorps are always good for a laugh, as are chaots who can spit acid.

Flooded tunnels are extremely hazardous, as most PCs need to strip down to their undies and swim carrying their armour in a bundle. Throw in a gorp or walktapus and the party is in big trouble.

Vampires can turn to smoke and exit through small cracks in walls, or prepared holes. They can be very hard to capture in that form, as I play that all their grave goods turn to smoke in the same way.

Getting to the cave system might have random encounters which might weaken the party before they even arrive. We had a cave crawl in the Big Rubble once and gave up after the random encounters killed 4 party members - thank goodness for Resurrection.

A well-prepared party will stock up on healing potions, antidotes and traded spells. If you go against undead then trade for Turn Undead, for example.

I am sure there are more things to consider, but those are the main ones off the top of my head.

Maybe I missed the point a bit.

I was talking cavern crawling, but the OP mentioned Mega-Dungeons.

I take it they are the same thing.

The closest thing I have run/played like that is clearing out Chaos Great Temples. They had probably half a dozen minor temples, with crazed initiates/rune levels, plus a Great Temple with over a thousand foes. We took weeks of gameplay to hammer through it, and at one point were standing on piles of corpses.

If that isn't what the OP meant, then I am sure that RQ could handle a mega-dungeon. Assuming that means a series of connected or unconnected habitats in a single place. Clearing out an orc nest, or a vampire stronghold, or series of caves, each with different inhabitants, all are eminently doable in RQ.

Quote from: Pete Nash;689684If you want to populate a dungeon with tons of foes such as goblins or undead, then utilise the Rabble or Underlings guidelines (p164 in RQ6 or make your own 'one-hit and they die/flee' rules) so they can cut a swathe through these foes, with a few proper encounters against opponents with about 20% less in their combat skill - to relish a bit of back and forth hewing - and a final BBEG or monster with comparative combat skills making the last battle particularly dangerous.

The important thing to remember is that RQ PCs are fragile, and remain so; unlike D&D where they start fragile but grow increasingly bullet-proof as they increase level.

This seems particularly good advice if you are taking a "level appropriate" approach to encounter building.

I thought that Snakepipe Hollow qualified as a mega-dungeon, or at least pretty close to one. I moved straight from B/X D&D to RQ2, by which I mean we actually converted our D&D characters over. I had only the Games Workshop deluxe box and for several years we basically played D&D with cults and battle magic. So, I don't see that there is any particular problem in running RuneQuest mega-dungeons.

One thing that was prevalent in Chaosium RQ was healing - players were just stuffed with healing magic, especially compared to D&D at the time which relied on clerics actually memorising healing spells. RQ healing really adds a lot to party survivability.

As someone mentioned up-thread, there might be a different factor that determines when parties want to make a break for it, and that's experience. You don't want to spend eternity slogging through a dungeon, because you won't get your experience rolls. Of course, that's different nowadays and even back then the referee could exercise discretion and allow experience rolls in mid-dungeon.

I don't know if you mean RQ in general or Glorantha specifically.  If I were going to do a megadungeon in Glorantha (of course feel free to scoff at the Glorantha n00b), I would try to take the "Mythic Underworld" idea of the megadungeon and work off that.

Maybe a 2nd Age temple complex to your Cult or Cults of choice, or ruined city from an earlier conflict, that is under "Mythic Assault" from the God-Learners.  As the PCs progress, they may or may not realize things are subtly changing and the whole extended dungeoncrawl is a Heroquest.

EDIT: or instead of the God-Learners, the PCs can get involved in a Heroquest stopping the return of some big bad from the dawn of time, like Temple of Tharizdun/Temple of Elemental Evil.

If you wanted to keep it non-mythic, and non-Glorantha, then without good access to Common/Folk Magic, people are gonna be dropping like flies in a standard D&D dungeon where things are more claustrophobic and there's a lot of bad guys.  Indiana Jones type dungeons with lots of exploration, and stuff to do without combat mixed in with some key encounters the players can have flexibility engaging would be a good idea.

If you wanted to do something like B2 in RQ, you could, but the players would have to be relatively higher skill level and better equipped to survive it.

I think it'd be trivial to come up with a good Gloranthan set up for a mega-dungeon, background-wise. It's not really what I'm after. I got an idea in my mind of course, but it's more related to classic mythology with a strong, gritty fantasy flair than anything else. I imagine the setting could be dropped into Glorantha with some tweaking, but it would work on its own, with its own specificities and cosmology, by default. Since the setting I have in mind incorporates a mega-dungeon type set-up (but not only), I'm wondering if it could work with RQ and if so, what that'd mean in terms of description of the underworld/dungeon to make it an interesting, dangerous place to explore and come back to regularly throughout the campaign.

The responses are really useful so far. Some things I was thinking about, like the lethality and factions and opportunities to engage conflicts and have cultural significance to it all rather than a treasure seeking default. Others I needed to see black and white on the screen.

Call it prospecting to see what might work, not work, what would need tweaking on my part to make it actually work at an RQ game table.

Great food for thought so far, in any case!

I didn't see many RQ dungeons apart from a few White Dwarf modules. And neither were even close to a megadungeon.
But I remember very well what Sean! also noted upthread: a tendency for hard-to-map caverns (The Black Broo of Dyskund).

A few non-Gloranthan but still very RuneQuest-y dungeons were in the Complete Dungeon Master Series (a series of boxed sets, dual statted for RQ and AD&D1), which were redone by GW for WHFRP as The Doomstones campaign.
It was a trip into a chaos-infected valley, following the breadcrumbs of an earlier expedition. Part of the fun of the modules was to figure out what exactly had happened decades earlier. In that it had a CoC-vibe as well, with lots of handouts and sketches.

Quote from: Dirk Remmecke;689750I didn't see many RQ dungeons apart from a few White Dwarf modules. And neither were even close to a megadungeon.
But I remember very well what Sean! also noted upthread: a tendency for hard-to-map caverns (The Black Broo of Dyskund).

Oh crap, I remember suffering through that one. A complete nightmare, from the mapping to the really evil encounters. Non-stop horror and tough to escape when Magic Points ran low and the tables turned...

Quote from: Benoist;689749I'm wondering if it could work with RQ and if so, what that'd mean in terms of description of the underworld/dungeon to make it an interesting, dangerous place to explore and come back to regularly throughout the campaign.

I have a fair amount experience running dungeons with low point GURPS campaign. (Not the 250 pt DF variety). The few times I ran or played Runequest suggest that the dynamic would be the same. Basically a result of character relying on skill and the possibility of being killed with one-shot regardless of experience.

Basically running a dungeon in GURPS is a mix of competence and fragility. Because of the skill based system characters have more assets to overcome various non-combat challenges. Even when you do the roleplaying there comes a point where a skill of Ancient Lore, Classical Era Art, Architecture, etc comes into play. Factors which are not present in a classic edition D&D megadungeon which mostly relies on players accumulating knowledge rather than characters.

Of course a referee could design a situation where none of the game's knowledge skills or mental skills come into play but then I have to ask why the referee even bothering trying to use that system then?

So there is that.

Then there is fragility of characters. Runequest seems to play out similarly to GURPS in this regard. The usual flow of combat is that the skilled character are able to maintain their position until a breaking point is reached and then they are crushed by the enemy.  This unlike the classic D&D I played where there is a whittling away of hit points. Until you hit zero there is no real consequence to the damage you take.

GURPS and Runequest not only have various states of incapacity prior to become unconscious a single blow can cripple the effectiveness a character.  And for both system characters find it very hard to handle multiple opponents unlike classic D&D.

My experienced players play very cautiously. They scout and setup ambushes whenever possible. They will try to find out what the place or area is like as a whole and then come up with a plan to achieve their objective without rousing the whole place. Even with considerable experience the party will not consider taking on 40 orcs all at once. In contrast a mid-level classic D&D party is probably can take on 40 orcs and come out top.

In addition in GURPS and I believe Runequest combat magic is on a far more personal scale than classic D&D. A mage in either system is a very deadly opponent to a individual fighter. But facing a mob head on there is little the mage can to do except to flee. A mid level classic D&D magic-user with fireball and similar spells has a chance of coming out on top when facing a mob.

Finally starting characters in GURPS and Runequest come off more capable than classic D&D starting characters. In my opinion it seems that a 150 pt GURPS characters feels likes 5th level classic D&D character, and a beginning Legends or 6th edition Runequest characters feels slightly lower between 3rd and 5th.

When I adapt or make original adventures GURPS, the approach I take is still the same broad setup but I try to approach the details realistically. If there is an area of orcs, I will set it up like a small village with living quarters, common areas, workshops, and a schedule of daily life.  Details that are important so that the characters can come up with other options than a head on fight.

I know many classic D&D referee do this but for GURPS, Runequest and similar games it important so that the party to has a fair chance of success.

Quote from: estar;689781When I adapt or make original adventures GURPS, the approach I take is still the same broad setup but I try to approach the details realistically. If there is an area of orcs, I will set it up like a small village with living quarters, common areas, workshops, and a schedule of daily life.  Details that are important so that the characters can come up with other options than a head on fight.

And two other things. One, specific to RQ6, is Luck Points. Basically while you have a Luck Point you can stay alive. Being captured is in many ways more likely than being killed.

Secondly, the easiest way of creating level equivalence is through NPC combat preparedness. If you assume that most NPCs don't exist in a permanent state of combat readiness, willing to fight with perfect discipline and adherence to optimal tactics at all times then the big advantage the PCs have is that they are the ones planning the violence. Of course, what naturally happens over time is that their actions precede them and NPCs they haven't met start preparing for the onslaught. So rather than facing higher level creatures, they start meeting better prepared opponents. The survivors of the trollkin mob they butchered 5 months ago has got organised and this time they're scary.

Quote from: deleriad;689789Secondly, the easiest way of creating level equivalence is through NPC combat preparedness. If you assume that most NPCs don't exist in a permanent state of combat readiness, willing to fight with perfect discipline and adherence to optimal tactics at all times then the big advantage the PCs have is that they are the ones planning the violence. Of course, what naturally happens over time is that their actions precede them and NPCs they haven't met start preparing for the onslaught. So rather than facing higher level creatures, they start meeting better prepared opponents. The survivors of the trollkin mob they butchered 5 months ago has got organised and this time they're scary.

Good points and I do to this as well as the other things I mentioned. One of the reason for a making a schedule of daily life is so that you can have NPCs in non-optimal situations (for the NPCs)