Subterrane Surveys: Gygax's Castle Greyhawk

We're incredibly fortunate that on August 16th, 2007, Matt "Eridanis" Bogen managed to take a few photos of Gary Gygax running his Castle Greyhawk adventure (for ENWorld moderators at Gen Con), catching glimpses of at least two maps and a key. The very fuzzy first-level key was mostly decoded with a great deal of effort from people like Allan Grohe (grodog), Zenopus Archives, and others. The evidence to my eye seems to be that was likely the true, original map of Castle Greyhawk (e.g., he wrote on the Pied Pier boards in 2004: "Fact is that I have run OD&D games every year at several cons for the last five or so years. I start them at 2nd level and use the old dungeon levels"; and Ernie Gygax has also recollected these match the earliest games). Let's assess the first-level key in detail.

Design: The dungeon design is of the fully-packed, use-every-space style, similar to what we see in the early Dungeon Geomorphs product, AD&D Module S3 (Expedition to the Barrier Peaks), etc. Many rooms are entirely empty, with no key code whatsoever. The Red Baron estimates there are about 160 rooms on the map; my own estimate is that maybe 40 have a key-code in them. That would be about 25% with any content at all -- similar to the guidelines in OD&D that about 33% have content (per 2-in-6 die roll; Vol-3, p. 7), the earliest Monster & Treasure Assortment suggestion that only 20% of rooms have monsters, etc.

Characters: Gygax's brief key doesn't state an expected party size. Recall from last week that neither do the core OD&D rulebooks. If we assume standard modern convention group size, then that could be maybe 6-8 people -- but recall also that in the earliest days a group might commonly be 12 or more people at once (e.g., see Jon Peterson, Playing at the World, p. 563, re: Gygax at Origins II). The question of what might be reasonable is, in fact, the whole point of our current investigation.

Monsters: The key for the level has 18 numbered codes; several are repeated in the map in clusters of up to a half-dozen located together (e.g., the kobolds, goblins, orc entries). All 10 of the monsters from the OD&D Monster Level Table 1 appear in this key. There are 3 from the Level 2 list (hobgoblins, berserkers, gnoll), and one each from Level 3 (giant snake) and Level 4 (giant beetle). One is novel (giant bats), and the last two keys have evil NPC spellcasters (2nd level magic-user and cleric, which could arguably belong on any of the 1st-3rd level lists).

Wandering monsters are not shown here, but if Gygax used them at all, it would make sense to simply use the book tables from OD&D Vol-3, because (as noted) they inherently represent the Castle Greyhawk ecology, and are a perfect match for the monsters present in lairs (see above).

Monster lair numbers are given in ranges of 3-7 orcs, 3-12 giant rats, etc.; very similar to what was suggested in Gygax's Monster & Treasure Assortment, and Holmes Basic D&D products. Using my "Equivalent Hit Dice" (EHD) analysis, I find that the average (mean and median) danger level of these encounters is 6 EHD, i.e., a fair fight for around 6 1st-level PCs. (There are reports that Gygax adjusted numbers to match the strength of PC parties present. Did he stay in the given ranges, I wonder?) The expected total strength for all the set encounters (ignoring duplications) is about 90 EHD.

Treasure: Almost every room with a monster has a treasure listed -- only 2 of 15 do not. This contrasts with the OD&D Vol-3 rule (p. 7) that half of monsters will have treasure; but it closely matches the Monster & Treasure Assortment rule that "about 20% of the monsters should have no treasure whatsoever". There is one room with no monster and a hidden treasure -- the largest reward on the level (room 8, with about 1/3 total value on the level). Note that with some key codes being duplicated, it's questionable whether every such room has the same treasure or not (unlikely that every kobold room has the same dusty silver mirror?), which would skew the treasure-to-monster ratio lower. The objects are clearly not from the monster-keyed Treasure Type tables, because coin values here are usually in the 10's (not 1000's as on that table; with one exception in room 4). Coin treasures are in the same basic order of magnitude as the OD&D dungeon treasure table (Vol-3, 7), without being exact matches. The gem values are usually in the 100's (as per book median gem type).

Total expected treasure (again, ignoring duplicated rooms) is about 4,400 gp. Given that, there are about 50 gp of treasure per monster EHD.

Magic: Magic is also relatively abundant. There are 6 of 14 treasures that have magic items (43% rate), for a total of 7 useful magic treasures; this includes 2 potions, 2 magic weapons, a magic shield, ring, and a staff (with 6 charges left). Contrast with the book rule that says only 5% of treasures at this level should have magic included (from which we might expect there to be none at all, given the total number of treasures here) .

Experience: Reports say that Gygax indeed used something like the Greyhawk revised XP system, as shared by B/X , AD&D, etc., instead of the original Vol-1 system (or maybe something simpler, like a flat 10 XP per monster HD?). For example, a play report from January 2008 with Gygax says, regarding area 18 above, "they got '20 xp from 1 gnoll' and '30 xp for the evil cleric'" -- which would be correct values per the Greyhawk chart for a 2 HD gnoll and a 2nd level cleric with double bonus for special abilities (suggested on Sup-I, p. 13).

So let's assume Gygax used the Greyhawk table, and each of the keyed areas only appears once. Then the total monster XP is about 2,000 and the total treasure XP available is roughly 4,400, for a grand total of about 6,400. This gives a monster: treasure XP ratio of about 1:2 (31% monsters, 69% treasure). Note that the total would only be enough to graduate 3 fighters to 2nd level.

On the other hand, if we use the original Vol-1 XP system, then the total of about 90 EHD would give monster XP of 9,000 or so, treasure the same 4,400, for a grand total of 13,400. Ratio would be inverted to about 2:1 (67% monsters to 33% treasure), and this would be enough to raise 6 fighters to 2nd level -- a good match for the 6 EHD average encounter here.

A few commenters have helpfully pointed out that there's at least a question about whether we should be adding XP from picking up and keeping magic items or not. There is a short line in OD&D suggesting as much (Vol-1, p. 18: "when they obtain various forms of treasure (money, gems, jewelry, magical items, etc.), they gain 'experience'."), but there are no rules or suggestions for what values to give them. Gygax gave a few examples in The Strategic Review Vol. 1, #2 (e.g., potions 250-500 XP, scrolls at 100/level, a sword +1 at 1000 maximum, etc.). Later in the AD&D DMG Gygax gave full XP valuations for all items in the game; they broadly match the Strategic Review values for potions & scrolls, with other items  mostly devalued (on the order of about a half).

As a rough estimate, the first level of Castle Greyhawk would give about 5,000 XP for magic items under either system. This would make a very significant difference; roughly adding 2/3 more XP under the Greyhawk system (constituting 44% of the total, and then very nearly promoting 6 fighters to 2nd level), or about 1/3 more under the original Vol-1 system (then 27% of the total, and promoting as many as 9 fighters to 2nd level). If we look at other adventures in the Basic D&D line, then this won't be a consideration, because XP-for-magic-items was entirely dropped in those rulesets (even after Gygax personally edited the Holmes Basic D&D set).