Sounds a bit wrong, that.
Coop of Fighting Fantasist tells me of a random dungeon generator for that noblest of classless sword-and-sorcery d6-fests ADVANCED FIGHTING FANTASY, which is good… but I don’t think the mechanic that’s being used is necessarily being taken to its full potential. Jaquays spoke of multiple levels, entrances and routes into and through a dungeon environment, moving beyond the linear into the topographically interesting, and you can read more of the principles of Jaquaying here. I’m not here to pontificate about principles (unusually!) but to offer some practical notions.
Where the d6 falls indicates the position of the room in the third dimension. The actual value on the d6 is a d3, indicating both the number of doors, and the elevation of the room in relation to others. The ‘higher’ of the two options that resolve into a d3 when you divide a d6 by two indicates that the room is physically above the previous one… look, it’s easier to show the results than the principle.
1 – one door, lower than previous room
2 – one door, higher than previous room
3 – two doors, lower than previous room
4 – two doors, higher than previous room
5 – three doors, lower than previous room
6 – three doors, higher than previous room
The dungeon’s designer is of course free to level it out (perhaps by ordering their creatures to jump up and down) at any point, but should in my opinion do so only if a group of organised, tool-using creatures has been involved in constructing an area (in which case they might conceivably want flat floors and sensible layouts).
Look for ways to link rooms back to one another, across another – like, if you have a 1 and then a 3 and then another 1, consider having a tunnel run between the two 1s as well as steps going up to the 3 (which then has a third door because you rolled a 6, leading into interesting places on its level). Even if you’re not going for sub-levels, at least having some slopes and steps helps enliven the atmosphere a bit.
For multiple entrances to the dungeon as a whole, consider either having the single die nearest the centre and the two dice nearest the edge as connecting passageways, linking the dungeon to either another layer of itself, or to the outside world. Actually, that might still be a little predictable. Maybe bung some different sized or coloured dice in to indicate ‘entrance/exit/portal’?
You could also use different sized or coloured dice to indicate whether a space is trapped (I have lots of green and red d6s, which lend themselves to an obvious colour code), what sort of creatures are in there (possibly mapping a colour or size or symbol-replacing-a-number of d6 to a faction), even if a room is actually a corridor (for our purposes a ‘corridor’ is just ‘a long thin room with lots of doors’.
Coop’s distance-across-the-map method for determining corridor layouts is all right but it tends to lead to a lot of straight lines, whereas I think that Jaquaying is better served by warping rooms to make corridors and treating them as rooms when employing random population methods like AFF’s inbuilt tables or, I dunno, the Tarot.
You could even extrapolate further with different die types indicating the shape or importance of rooms, with the important thing being that you always use die roll / 2 to give the indication of higher/lower (although good old Fighting Fantasy uses d6s across the board, perhaps for reasons such as those illuminated at The Sustainable Centre the other week).