a matrix of interconnected rooms

 In the essay "Figures, Doors and Passages," Robin Evans contrasts the Classical and Renaissance approach to dividing rooms into spaces with the Modern (post-19th century) ideas about the same. As the main example of the former, he discusses the Villa Madama:

The first difference he points out from modern plans is that:

...the rooms have more than one door - some have two doors, many have three, others four - a feature which, since the early years of the nineteenth century, has been regarded as a fault in domestic buildings of whatever kind or size. Why? the answer was given at great length by Robert Kerr. In a characteristic warning he reminded readers of The Gentleman's House (1864) of the wretched inconvenience of thoroughfare rooms, which made domesticity and retirement unobtainable. The favored alternative was the terminal room, with only one strategically placed door into the rest of the house.

Yet exactly the opposite advice had been furnished by the Italian theorists who, following ancient precedent, thought that more doors in a room were preferable to fewer. Alberti, for instance, after drawing attention to the great variety and number of doors in Roman buildings, said, 'It is is also convenient to place the doors in such a Manner that they may lead to as many parts of the edifice as possible.' This was specifically recommended for public buildings, but applied also to domestic arrangements. It generally meant that there was a door wherever there was an adjoining room, making the house a matrix of discrete but thoroughly interconnected chambers. Raphael's plan [of the Villa Madama] exemplifies this, though it was in fact no more than ordinary practice at the time.

In modern design, enclosed spaces are distinguished between access spaces to be moved through but not occupied (elevators, passages, stairs) and those that are meant to be occupied but not moved through (rooms). However in earlier eras, even buildings large enough to be subdivided into many rooms (it is worth remembering that most buildings would contain few rooms; even a king might have no more than a hall, a private chamber for his family and a kitchen in his castle) would generally favor what Evans calls the "matrix of interconnected rooms."

This contrasts markedly with the kind of dungeon plan perhaps best exemplified by Castle Geryhawk, in which mostly-empty passages serve isolated terminal rooms to be stocked with various monsters or treasures:

The Greyhawk map is quite interesting because it demonstrates an extremely modern layout sensibility in an ostensibly medieval complex. The language Evans applies to William Morris's plan for the Red House at Bexley Heath applies perhaps more directly this dungeon than the house itself:

Yet his commitment to past practice only went so far. The morality of craft and beauty might transform the procedures of building and the appearance of the finished work, but medievalism did not percolat into the plan, which was categorically Victorian and utterly unlike anything built in the fourteenth or fifteenth centuries. Indeed the Red House illustrates the principles laid down by the bourgeois Robert Kerr better than Kerr's own plans: rooms never interconnect, never have more than one door and circulation is unified and distinct.

That may have been said to Morris's shame, but I don't mean it to shame the Castle or its designer. If anything, its plan is less typical of modern dungeons than the kind of dungeon plan perhaps best exemplified by (my beloved) Nethack, wherein corridors lead from specific rooms to specific other rooms, rather than forming a network of circulation for the whole level:

However, I think embracing the matrix of interconnected rooms is a useful tool to keep in mind when designing dungeons or other structures because it naturally introduces a high degree of interconnectivity and makes chance encounters with the inhabitants of the dungeon likely throughout, not simply in their designated areas or when they take to wandering the halls. Here are a last few thoughts in the form of suggestions when drawing a dungeon plan:

• When possible, place rooms that connect next to one another without an adjoining corridor.
• Don't put an isolated room at the end of a corridor unless there's a particular reason for it to be separated from the others.
• If many rooms lie on a single passage, consider making it a courtyard or loggia (above ground) or an atrium or other vertical space, perhaps with access to other levels (if below).