Don Turnbull on the Sample Dungeon as "Coherent" dungeon design

THE PHOENIX (later just PHOENIX) was "A British Board Wargamers Magazine" published by SimPubs, a UK affiliate of the company SPI, from 1976 until 1982 (36 issues total, which are available here on spigames.net). As Dungeons & Dragons ramped up popularity during the era of Holmes Basic, Don Turnbull wrote a semi-regular column for this magazine called "D&D: Notes from the Underworld" (likely a play on Dostoyevsky's Notes from the Underground). It started in issue #15 and ran for eight installments, with the last in issue #26 July/August 1980. An editor's note at the top of his first column indicates that his column will serve to introduce D&D to wargamers:

"I am pleased to welcome Don to these pages. Without much fear of contradiction I can say that he is one of the small band that first really brought boardgaming to our shores in the far off halcyon days of Poultron Press [an early name for SPI — Z]. His deep experience of the hobby is reflected in anything that he turns his hands to - D & D is no exception. It his hoped that his regular articles on this and other games of a similar nature will enable us all to appreciate what some amongst use are wont to call 'unreal wargames'! Note his comments on feedback — we are waiting!"

Don Turnbull (1937-2003) started his career in gaming by publishing a Diplomacy zine, Albion. He was an early D&D enthusiast in the UK, running an OD&D megadungeon named the Greenlands (after the street where he lived), a few sections of which were published in White Dwarf and Dragon magazines. He rose to prominence in RPG circles working for White Dwarf, writing reviews and editing the Fiend Factory column compiling new monsters by various contributors, which he later turned into the Fiend Folio (1981). He went on to run TSR UK, publishing Imagine, the UK analog of Dragon magazine, to which also contributed a regular column. During this period he co-wrote TSR's classic U1-3 series of modules with Dave J. Browne and oversaw the UK module series. He next worked with Gary Gygax in his ill-fated post-TSR company New Infinities Productions. He continued to run D&D games - set in Greyhawk's County of Urnst - for his friends until he passed away in 2003 at the age of 66.

A photo of Don at Games Day III (17 Dec 1977) with the new UK printing of the Holmes Basic set appeared in White Dwarf #5 (Feb/March '78): 

"Dubious characters handling dubious material! From left to right, Bill Howard, Don Turnbull, Tony Ball and Rob Thomasson". However, based on the below photo, I think Don is actually the one wearing the plaid tie.

In 2016, Ian Livingstone of Games Workshop posted on Twitter a photo of Gary Gygax, Turnbull, himself and Steve Jackson (the UK one) in 1979:

The second installment of his column for the Phoenix (in issue #16, Nov/Dec 1978), is devoted to dungeon design, including distinguishing what he describes as "incoherent" and "coherent" designs, and the strengths and weaknesses of each. As an example of "coherent" design he cites a certain dungeon very familiar to us:

"The coherent design requires much more initial work. First the DM must invent a rationale for the design — give the dungeon a history and provide reasons why it should be more or less as it is. The new edition of the TSR rules [the Holmes Basic set — Z] contains a good example — the cellars and tunnels beneath a sorceror's tower which, since the mysterious death of its architect, are rumored to contain fabulous treasure and unspeakable monsters. Such a rationale might be made available to the players, int he form of local legend perhaps, before their characters can penetrate the dungeon; or it might simply serve as the DM's private source of design ideas. 

Of course, the coherent style is far from convergent: there will almost certainly be elements of incoherence within it. In the TSR example, the sorceror's tower will have some areas of random or near-random occupancy — who can tell what monsters have made their lairs in its myriad passages and rooms? Was the death of the sorceror caused by an invading party of monsters in the first place? There is plenty of room for flexibility here. 

Once the 'history' has been devised, the design flows from it, and in my limited experience designing comes somewhat easier at this stage than in the incoherent style. In the TSR example, the sorceror would have had sleeping quarters, a study and/or laboratory, a trophy room perhaps, a library, some servants' quarters, a dungeon in which he used to incarcerate potential victims of his experiments etc. Some of his personal possessions (scrolls, magic books, artifacts) might have survived if they were carefully hidden. His faithful manservant may even still be doddering around wondering what has happened to his master but determined to keep the place tidy in readiness for his master's return. The trouble with coherent designs is that they tend to be limited in the physical sense. Even if the sorceror had created a large 'lair' it won't take long for a visiting party to ransack the place. If a designer is to create a setting large enough to keep his players occupied for a long series of adventures, he must thing bigger than this. Nor, in the end, will he be able to get by with a sorceror's tower here, an Orc stronghold there, a Dragon's nest in the interior of the hill, and Undead area below the local burial ground and the like. Sooner or later, in connecting all these parts to form a whole, he will come to the point at which the coherence drifts away — he may even come to a point at which his imagination refuses to conjure up another rationale."

There are interesting ideas here for expanding the Sample Dungeon, some of which I've touched on myself over the years:

-Invading monsters, still in the dungeon, presumably on a lower level "where Zenopus met his doom". Possibilities that come to my mind include Holmes' Dagonites (analogs of the Deep Ones), Ancient Builders, Lovecraft's Mi-Go (which I call Whisperers), D&D's Troglodytes, or some kind of Green Flame manifestation, which I used in the d12 Hauntings of the Zenopus Dungeon.

-Living quarters for Zenopus such as a bedroom, study, laboratory, trophy room (B1 In Search of the Unknown has one of these), library, servants' quarters, and/or prisoner dungeon. Some of these would more likely have been in his destroyed tower, but it does give some possible ideas for filling in some of the empty areas in the basement, or for a modified adventure set closer to the disappearance of Zenopus when the tower was still intact.

-A hidden cache of wizardly possessions. Along this line, when I've run the original I've placed an old "Storage Room" in the empty room south of Room J (the Spider's Lair), which I've been meaning to write up here for quite a while.

-A former servant of Zenopus still wandering about, waiting for his return; I especially like this one, although it is more logical with an adventure set closer to the disappearance of Zenopus before the tower was destroyed by the town. The intro to the dungeon mentions that some of his servants escaped the immolation of the tower and I used one as a source of a rumor in Portown rumors. I also placed a former creation of Zenopus as one of the wandering monsters in my 5e adaptation of the dungeon, and have former familiars (the "goblin figures") in the aforementioned d12 Hauntings.

Turnbull's later U series of adventures is  a logical extension of his idea of coherent dungeon design. And the haunted house in the first module, U1 The Sinister Secret of Saltmarsh certainly has some similarities with Holmes' Sample Dungeon, such as a missing "wizard" and an underground connection to sea caves harboring smugglers. Thus, the development of the U-series appears to have been influenced by Turnbull's earlier encounter with the Sample Dungeon in the Holmes Basic set and his view of it as a strong example of "Coherent" dungeon design.