Monday, August 21, 2017

Exploration Movement Rates

How long would it really take to explore a dungeon or cave? I'm just talking moving through the place and roughly mapping the perimeter. Not included: Searching through chests, desks, libraries; looking for secret doors; disabling puzzles or traps; spelunking through tunnels; etc. It does presume at least being on the lookout for possibly dangerous animals or enemies. It's hard to say how you'd even be able to measure this.

Here's the best stab I can take at it so far: the U.S. National Park Service has a very nicely laid-out website for Mammoth Cave National Park in Kentucky. In particular, it details over a dozen different tours on the site, including specifics for duration, distance, and difficulty. From these we can compute the average speed on these cave tours:


Method: The first four columns above are transcribed from the NPS website; "difficulty level" is an enumeration I added for the different difficulty descriptors; and speed is calculated as expected. Side observations: The "Trog" tour is, perhaps ironically, for kids only. The "Violet City Lantern" tour uses only open-flame lanterns (no modern lights) so as to recreate the experience of exploring the caves -- and living in an underground tuberculosis hospital that was located there -- in the early 19th century. (This latter sounds like among the most interesting to me!)

Conclusions: The speeds on these tours range from a minimum of 0.2 mph to a maximum of 1.5 mph, with an average of 0.7 mph. There is effectively no correlation between difficulty level and speed (R² = 0.04). For example, the "Easy" difficulty tours include both the slowest and the fastest speeds. There is a statistically negligible trend for the more difficult tours to be a bit faster.

Can we use this as a metric to properly gauge dungeon exploration speeds? Obviously, the experiment lacks many things: They are all safely pre-mapped routes, no one is in fear of being attacked, they're being led by knowledgeable guides, etc. On the other hand: The tours all have to account for civilians in all kinds of shape, they are organizing fairly large groups, the guides are stopping for discussions and questions, they're being environmentally careful (unlike tomb-robbing adventurers), they go up-and-down through rugged cave areas (whereas dungeons are mostly level constructions), etc. I'm sure the data is biased one way or the other, but I can't tell which.

Let's look at the exploratory move rates in OD&D. First, recall that standard human walking/marching speed is around 3 mph (from whence we get the "league" unit). OD&D sets basic encumbrance levels and move rates on Vol-1, p. 15 (and these are basically copied from Chainmail), with the exploratory turn movement in Vol-3, p. 8. This latter is described as "ten minutes to move about two moves -- 120 feet for a fully armored character". In summary we get this:


So that's pretty slow; only about 1/4 mile per hour for unburdened men; or, approximately equal to the slowest (and easiest) tour at Mammoth Cave Park. Of course, AD&D reduced the rate even further, dictating not "two moves" but only a single move of 10' per inch in a 10-minute exploration turn -- that is, half again slower than the numbers in the table above (1/8 mph at the maximum). The OD&D rate is slow, while the AD&D rate is very slow.

So today I'm thinking that those movement rates are probably too slow. Consider the following: These days I'm in the habit of using half-hour exploratory "turns". That seems like about the right pace for wandering monster checks, and it's also scaled to the approximate number of encounters per game session (e.g., many tournament writing guides suggest planning on about 7 encounters in a 4-hour game slot, plus time for setup; and in my experience this is roughly accurate). If we set exploratory movement conservatively below the average Mammoth Park tour speed, at say 1/2 mph, then this conveniently converts to nearly MV (in inches) × 100 feet per half-hour. This proposed rate is shown below:


Obviously, that's roughly double the exploratory move rate given in OD&D Vol-3 (and 4 times the rate seen in AD&D). On the other hand, it's half the underworld tunnel move rate specified in module D1-3, on the order of 1 mph  (one mile per MV per day, that is, 12 miles in a day for a person with 12" move). This seems possibly about right. It also seems roughly to scale with what my players cover in real gaming time when exploring and mapping, which I like as a usable rule-of-thumb. Of course, extensive area searches, fighting encounters, etc., add to this simple movement figure. Movement through previously mapped/cleared areas can be at a rate of 5 times this (as in AD&D PHB), so around 2.5 mph, a bit less than normal walking speed.

Can you think of any better way to model dungeon exploration move rates with real-world experimental data?


Saturday, August 19, 2017

Saturday Survey: Dragon Breath

I've taken the opportunity to ask a few polls on the AD&D 1st Edition Facebook group. Today: Does the damage from dragon breath get reduced after the dragon takes damage?

The AD&D Monster Manual is certainly ambiguous in its statement that "The breath weapon causes damage equal to the dragon's hit points (half that amount if a saving throw is made) on each and every creature hit by the breath weapon." (p. 30, 1977). This is somewhat frustrating, because the ambiguity could be cleared up with the addition of a single word, either "current" or "maximum". Of course, the D&D Basic line (Moldvay/Mentzer/Allston) does specify "remaining number of hit points" (in boldface in Moldvay p. B34). Somewhat less well-known is the fact that the AD&D Fiend Folio dragons also specify damage by "current hit points" (entries on p. 28-29, 1981). On the other hand, the OD&D language gives a damage amount "per [hit] die", which in the most literal reading leans in the direction of being disconnected from the dragon's actual hit points.

One interesting thing is that a close reading of the texts up to 1978 seems to indicate that Gygax (et. al.) simply had no language available to distinguish between current hit points and maximal hit points for a given character. For example, here is an excerpt from the AD&D PHB section on Character Hit Points (p. 34, 1978):
Hit points can be magically restored by healing potions, cure wounds spells, rings of regeneration, or even by wish spells. However, a character's hit points can never exceed the total initially scored by hit dice, constitution bonus (or penalty) and magical devices. For example, if a character has 26 hit points at the beginning of an adventure, he or she cannot drink  a potion or be enchanted to above that number, 26 in this case.
Note the convoluted formulation "total initially scored by hit dice, constitution bonus (or penalty) and magical devices" in lieu of the shorter modern, phrase "maximum hit points". You can search all through the MM and PHB and never find either the phrase "current hit points" or "maximum hit points". The same is nearly true for the DMG -- the phrase "maximum hit points" does appear twice, but in this context it means the maximum possibly rolled, i.e., getting all of 8 pips per die (e.g., paladin's warhorse p. 18; reincarnated badger p. 44). Another example of the ambiguity of not having this linguistic distinction can be found in the discussion of Energy Draining (DMG p. 119).
 Back to the topic of Dragon breath. I find that what makes this topic unusually contentious is that whatever convention one is accustomed to playing with, most players will argue that it is "obvious", perhaps mis-remember some explicit statement in the Monster Manual making it so, and in many cases take offense at any suggestion otherwise. (Hey, Internet, y'all.) At any rate, asking this question on the Facebook AD&D form prompted an unusually large, boisterous, and lopsided response.


So with N = 142, only 16% of the respondents said "Yes", with 84% saying "No", on the issue of whether dragon breath effect is reduced by damage on the dragon.


Monday, August 14, 2017

Oozes Through the Ages

Gygax liked his oozes. Most of the monsters in Original D&D (Vol-2) were either creatures out of Greek myth, or else monsters from Tolkien. The ones that were new to the game itself, created by Gygax, were the "cleanup crew" of scary amoeboids: ochre jelly, black pudding, green slime, and gray ooze. I got looking at these the other day and was surprised at how vague their functioning was, and how much they varied between editions. We've pointed out before that the Black Pudding is actually one of the most powerful monsters in the original game. Let's dig a bit deeper.

Original D&D

BLACK (or GRAY) PUDDING: Another member of the clean-up crew and nuisance monster, Black Puddings are not affected by cold. It is spread into smaller ones by chops or lightening bolts, but is killed by fire. Black Puddings dissolve wood, corrode metal at a reasonably fast rate, have no effect on stone, and cause three dice of damage to exposed flesh. If an armored character runs through a Black Pudding the monster's corrosive power will eat away the foot and leg protection of the armor so that it will fall-away next turn. Black Puddings can pass through fairly small openings, and they can travel as easily on ceilings as on floors.

One of the things I like about OD&D is that the monsters are sorted by category (all the humanoids, then all the undead, etc., usually by increasing power level). This makes it a bit easier to assess the common themes and features, and their differences, in monsters of a particular class. For space purposes I've just excerpted the Black Pudding above, the most powerful type, but you can see the others on the same or flip page in Vol-2 (p. 19-20), and they generally have the same format of description. The description specifies what kinds of attacks have effect, what kinds of materials are dissolved, and how much damage the thing does to flesh per round. Note that in OD&D, the only attacks that do damage in the system are of type fire, cold, lightning, or martial weaponry; when this was copied to future editions, it looked a bit strange, for not mentioning all the other types of damage that then existed. Here's a summary of the traits of the different oozes in OD&D, ranked in increasing level:


Note that in every case, as hit dice improve, so too do movement and armor class (monotonically). As noted, Black Pudding is the most powerful type -- immune to all attacks except fire exclusively (consider: what if you encounter one underwater?), dissolving all materials (except stonework), and doing the most damage of any creature in the game (3d6). The ochre jelly is like a half-strength pudding; vulnerable to twice the attacks (fire and cold), no effect on twice the materials (metal and stone). Gray ooze is effectively the inverse of ochre jelly; immune to the attacks that harm jelly, harmed by jelly's immunities, and reversed effect on non-stone materials (swapping wood for metal consumption). Green slime is the dumb, immobile cousin; harmed by the same attacks as jelly, and consuming all materials except stone.

Excepting the jelly, each of these types makes noise about eating away a character's metal armor, but the mechanic is left vague, possibly for each DM's adjudication on the fly. Reading the Black Pudding text above, I could imagine a whole host of possible ways of ruling on it:
  • Ooze makes normal to-hit rolls.
  • Ooze ignores armor for hits (always AC 9)
  • Armor is corroded only on a normal hit.
  • Armor is corroded on a miss (i.e., blocked by armor)
  • Weapons may or may not corrode on a hit.
  • Gray ooze, affected by "cuts and chops" may or may not only allow hits by swords and axes (disallowing clubs, spears, missile weapons). 
 What to do? So, I was looking to other editions for guidance.

Basic D&D

Gray Ooze: This seeping horror looks like wet stone and is difficult to see. It secretes an acid which does 2d8 points of damage if the gray ooze hits bare skin. This acid will dissolve and destroy magic armor in one turn. After the first hit, the ooze will stick to its victim, automatically destroying any normal armor and doing 2d8 points of damage each round. Gray ooze cannot be harmed by cold or fire, but can be harmed by weapons and lightning.
Holmes (1978), as usual, only restates what is in OD&D, with most of its oddities still intact. The text above is from Moldvay (1981), and the new feature that he has introduced is the fact that the ooze is sticky: "After the first hit, the ooze will stick to its victim, automatically destroying any normal armor and doing 2d8 points of damage each round," which is not something I would have ever intuited from the OD&D description. However, this particular feature is not included for ochre jellies in the same text, or for black puddings in Cook's Expert rules. These descriptions remained fixed through the Mentzer and Allston editions.

AD&D 1st Ed.

BLACK PUDDING: The black pudding is a monster composed of groups of single cells. It is a scavenger/hunter found only in underground areas normally. The body structure of a black pudding  is  such that it con pass (flow) through narrow openings (such as a  1"  crack under a door). The monster travels equally well on walls or ceilings as well as floors. Its tiny mouths and saliva do 3-24 hit points of damage per melee round to exposed flesh. If the monster needs to dissolve wood in order to obtain food, it can eat away about a two inch thickness of wood equal in area to its diameter in  1  melee round. Black puddings also eat away metal with their corrosive saliva: Chainmail in 1 melee round, plate mail in 2, and an additional melee round for magical armor at a rate of 1 melee round for each plus of armor. Thus, +1 magic (plate) armor would have to be in contact with a black pudding for 3 melee rounds before it dissolved. If chopped or struck, the monster is broken into two or more parts, each able to attack...
In the AD&D Monster Manual, we get a little more info about how quickly the pudding eats armor (chain in 1 round, plate in 2 rounds... note that in OD&D the text here said "turn", which I argue meant a Chainmail-style single 1 minute of combat at the time of writing). But this doesn't help resolve the question of exactly when armor starts to corrode, or the other questions noted above. Gray ooze refers back to this text for its own armor corrosion; it suggests for the first time, "Note, however, that in the latter case the weapons striking the creature may corrode and break.", but is not explicit about when or how likely that is to occur.

AD&D 2nd Ed.

The 2E descriptions show no important differences from the 1E text. The effective attacks, damage, materials consumed, and time to corrode metal are all exactly the same. No further detail is given on when to adjudicate the corrosive effects of the oozes.

D&D 3rd Ed.

Black Pudding

Improved Grab (Ex): To use this ability, the black pudding must hit with its slam attack. If it gets a hold, it can constrict.


Acid (Ex): The pudding secretes a digestive acid that dissolves organic material and metal quickly. Any melee hit deals acid damage. The pudding’s acidic touch deals 50 points of damage per round to wood or metal objects. The opponent’s armor and clothing dissolve and become useless immediately unless they succeed at Reflex saves (DC 19). The acid can dissolve stone, dealing 20 points of damage per round of contact. A metal or wooden weapon that strikes a black pudding also dissolves immediately unless it succeeds at a Reflex save (DC 19).


Constrict (Ex): A black pudding deals automatic slam and acid damage with a successful grapple check. The opponent’s clothing and armor suffer a -4 penalty to Reflex saves against the acid.
Split (Ex): Weapons deal no damage to a black pudding. Instead the creature splits into two identical puddings, each with half the original’s hit points (round down). A pudding with only 1 hit point cannot be further split.
Now with the 3rd Edition game, we do get added information that perhaps answers the questions we've been asking since OD&D. Black pudding is given abilities of "improved grab" and "constrict" that fold its mechanic into the more general rules on grappling in the 3E system; the monster must first hit, then can hold an an opponent as long as they do not counter, but require an additional check each round to actually do damage. In this sense it is "sticky" in a way only previously seen in Moldvay's gray ooze text. Weapons explicitly need a saving throw on contact or else they, too, corrode away. In 3E, each of the oozes considered here -- black pudding, ochre jelly, and gray ooze -- all work in this fashion. (In this edition, green slime is removed from the monster list and placed in the DMG under "Organic Hazards").

Poll Results

I asked my list of questions about ooze corrosion on the Facebook 1st Ed. AD&D group. This did not get nearly the attention that some other poll questions did (like, e.g., the question on how to adjudicate damage from dragon breath) -- seemingly this was not an issue that most people had strong opinions about. The majority choice, however, surprised me:


I say that this is surprising because -- while the group is dedicated to 1E AD&D rules, and is often downright militant about those texts' rulings -- in the case the preferred rule was the one from Moldvay's B/X (and echoed in 3E). Of the 26 respondents, most (54%) do like their puddings and oozes to be "sticky", which is not a trait suggested in either OD&D or AD&D. Only about one-quarter (27%) require the metal armor to fall off before attacking the "bare flesh". Only a single person was fond of corroding weapons that strike the ooze. No one selected any of the variant options for assessing when an ooze strikes a victim, or possibly corroding armor when failing to hit the person wearing it.

Conclusions

While OD&D/AD&D is ambiguous about adjudicating ooze armor corrosion, the editions that are explicit -- B/X for gray oozes, and 3E for all of the types -- make the oozes "sticky", effectively grappling victims automatically after the first hit; and it seems like the cultural memory of even AD&D players has incorporated this ruling. Perhaps this is the best way to rule on the creatures because, after all, a "grappling" type attack is in fact how real-world amoebas really capture their prey.

What do you think? Any other possible adjudications that I've overlooked?

Saturday, August 12, 2017

Saturday Software: G1-3 Giant Bag Generator

 In Gygax's AD&D Dungeon Modules G1-3, there's a table for generating the contents of Giant Bags and other containers like chests, boxes, etc. It's a bit unwieldy in practice because the recommended usage is to generate between 5-20 items per bag. I've found it useful to pregenerate a number of such containers, and have cards to hand out to players during the session.

Here's a Java program to do that job for you. One run generates 10 random "packs" (so named to cover the various bag/chest situations). Each is coded with a letter A-J so you can note it in your adventure where each one comes from (if you so choose). Run on the command line and copy-paste to a word processor set up with business-card-sized labels. Or just use the sample output run below. Print, cut, and drop them on your players when their encumbrance levels least expect it.


Thursday, August 10, 2017

Infravision per Westworld

On the Facebook AD&D group, Gygax Jr. asserts that infravision was intended much as the vision of Yul Brenner's character from Westworld (1973):



Monday, August 7, 2017

Unexpected Lycanthrope Rulings

Discussions on the Facebook 1st Ed. AD&D group (which has over 8,000 registered members) resulted in a surprising observation; a very large number of players/judges there rule attacks on lycanthropes like werewolves in an unconventional fashion. In particular, lots of people give lycanthropes regenerative powers which are only foiled by silver or magic (analogous to a troll's regeneration which is only foiled by fire or acid). Considering the AD&D rule that allows creatures with at least as many hit dice as an ogre to "effectively hit" lycanthropes, I was inspired to ask a few polls there, the final one being as follows:


Note that of 45 responses there, fewer than half (21/45 = 47%) picked the top answer which I'm fairly sure is the by-the-book rule. Almost a third (14/45 = 31%) rule by fiat that the lycanthrope cannot die from any such attacks (possibly remaining comatose or in stasis until such point as they can heal like a normal creature). About one-sixth (6/45 = 16%) make the rather astounding interpretation that they take damage from such attacks, but are instantly regenerated from them. A small number (3/45 = 7%) simply ignore or house-rule that mechanic out of their games.

I was surprised by the frequency of that. Of course: some commentators are aware that they're making house-ruled modifications, while others are adamant that their interpretation (like instant regeneration) is the intended by-the-book rule. Does this match your gaming experiences? Is it truly so widespread to make alternate rulings to how lycanthropes respond to damage?


Thursday, August 3, 2017

Thiefly Thursday: Running & Climbing Videos

Just in case you didn't seem them in the comments under the Climbing Through the Ages discussion, here are two excellent videos you should watch of athletic activities researched in plate armor (thanks to Rando and Joshua Macy for pointing these out):