OED on Roll20

OED Character Sheet on Roll20

Hey, did you know there's an official Original Edition Delta Character Record Sheet available on Roll20? Yessiree Bob, there sure is.

This a joint work between myself and Jameson Proctor (Campaign Games, Forts & Frontiers), to whom I'm immensely grateful for starting this project. The sheet's actually been online for over a year at this point, but I just recently found some time to make all the OCD/OED tweaks that would make me extra-happy to use it myself.

We've tried to keep it fairly lightweight and flexible so DMs have the freedom to adjudicate details to their personal taste. But for convenience, we've added these webby features:

  • Auto-calculation of ability score bonuses.
  • Auto-calculation of movement rate from encumbrance.
  • Push-button for saving throws (based on character level).
  • Push-button for attack rolls (rolling both attack & damage).
  • Auto-summing of equipment encumbrance values.
  • Checkbox interface for memorizing spellbook entries.

When you're making a new game on Roll20, or updating an old game via the Settings > Game Settings > Character Sheet Template menu, you can scroll down to "Original Edition Delta" -- or just search for "delta", and that will bring it up.

Hopefully this will suit your purposes if you're playing our style of lightly-adjusted old-school game. I like to think I'm pretty good at testing & debugging this kind of work, so it looks pretty solid to my eye at this time. But please check it out and leave a comment on anything you think I missed.

Fight on!


Radius or Diameter?

Circle circumference, diameter, radius

I've been working on refining spell descriptions (again) lately -- for hopefully upcoming expanded releases of the OED Book of Spells and Book of War rules. (E.g., we started testing top-level spells in mass battle play in the BOW livestream sessions the other week.) A couple of recent testbeds brought to mind the question: what's better for expressing the area of a circular spell effect, the radius, or the diameter?

For many years I've been strongly biased towards using the radius, because that's the used in mathematical definition of a circle. Arguably, however, it's easier and more common to measure real-world existing circles via the diameter (given the center is not actually part of the circle or necessarily distinguished; think tires, pizzas, wells, etc.)

Funny observation: Gygax's writing for O/AD&D was amazingly inconsistent on the matter, often flip-flopping for various spells in opposite directions. Starting with the first few spells in the Chainmail list, I see:

  • Chainmail: Catapults/fireballs given by diameter, light by radius, protection from evil by diameter, etc.
  • Original D&D: Fireballs by radius, light by diameter, protection from evil by radius (so, each of example toggles)
  • Swords & Spells: Everything by diameter.
  • Advanced D&D: Everything by radius (as far as I can tell).

I think the Swords & Spells case is interesting, because it gives a big list with all the stats (range, area, duration) for every spell in OD&D in a master list. When I did the same thing for my simulator, I found that things got confusing for a specific reason -- every other shape was being expressed by overall width (squares, lines, cubes, rectangles, etc.), but circles were listed by half-width. So I was getting a bit scrambled comparing entries of "circle-2-in." next to "square-3-in." and remembering that the former is actually bigger (wider). Note this is the case where Gygax gave diameters for everything, and I think this explains why.

The other (and related) case is trying to build templates for area spells in a VTT, specifically Roll20. There's a single pipeline for importing a token image and specifying how big it should be in map-square-units, and that interface asks for the total width (whether the image is of a square, rectangle, circle, etc.). So for my circle areas I was having to do an extra mental step and remember to double the indicated rule dimension for each token. In addition, I'd note that hand-drawing circles, ellipses, etc. in Roll20 and most drawing software I'm familiar with involves drawing and reporting on the bounding box for the shape in question; they don't draw from center to circumference.

Based on these experiences, for consistency with other shapes, I had an urge to switch all the circular specifications from radius over to diameter. But I also thought to ask opinions online, and got feedback like this on the ODD74 forums:

Poll: Radius (17) vs. diameter (0).

Similarly, folks on Twitter were almost unanimously in favor of using the radius. Voting on the Wandering DMs Discord server also went for the radius (with some votes switching from diameter back to radius based on discussion there: esp., targeting and determining casualties for a blasting spell). I didn't bother to ask on an AD&D forum, since those rules do uniformly use radius, so I assume everyone will be habituated to that.

Therefore, I'm taking that as an overwhelming preference among the classic D&D community, and not indulge my momentary instinct to switch things to a Swords & Spells type presentation, but instead keep giving radius like everyone expects.

We're all lucky I didn't find some way to argue for the circumference.


Dragon's Lair

Dragon's Lair cover

I've gotten a chance to play the Dragon's Lair arcade game on my PC (finally in the last week or so).

I can't emphasize how ground-breaking this game was when it showed up in arcades back in 1983 (40 years ago as I write this). Up to that point, we'd only seen 8-bit sprite-based games with digital audio blips. Consider the top games from 1982 (per Wikipedia, "the peak year for the golden age of arcade video games") -- Dig Dug, Pole Position, Zaxxon, Q*bert, Time Pilot, etc. Rendered 3D games were about a decade away at that point.

And then all of a sudden the Dragon's Lair cabinet shows up with Laserdisc technology, and you're playing through a full-on Disney-quality animated movie by Don Bluth & co., experiencing booming professional voice acting, etc. My brain still hasn't recovered from what a leap it was.

For years I've tried to get a PC version working and never succeeded. I think I bought at least two CD versions and each time they were broken beyond usability. This past week I decided to do another search and, amazingly, managed to get a version that actually works. Plus the sequels: Dragon's Lair 2, Space Ace, etc.

So I'm playing through and actually learning how to play and decoding the terrifying puzzles for the first time. An amazing trip.

Here's a point: I'm finding that I don't like the sequels nearly so much. This is not remotely a nostalgia thing because, for budget reasons, I really never played any of them back in the day more than once or twice. So, why this preference?

It's because the later iterations made that classic misstep (to me) of inserting more story into the games. The first Dragon's Lair is essentially a picaresque: the action sequences come in basically a random order, and you never know what's coming next. Part of the play is keeping on your toes and identifying each scene quickly as it starts, so as to engage the right move series. This randomness keeps replayability high, and keep the focus tightly on the player skill in each puzzle as you learn and gain expertise with it.

But then each of the games afterward make the Hickman-esque movement of "this game would be better if it was more like a story you'd see in a book or movie". There are more narrative sequences of people talking when you don't have anything to interact with. More importantly, the sequence of scenes is always exactly the same for every play-through, because it needs to keep on a tightly railroaded plot. I find this has three effects: One, replays get boring faster because of the predictability. Two, it's more likely that you replay parts of the same scene back-to-back because the scene needs to get completed before you can continue. Three, when it mulligans you and just pushes you forward after a failure (death), I find that weirdly more jarring, because the Kenny-like death in the middle of the narrative story seems more lampshaded-incoherent.

This sense is of course consistent with my discomfort with the historical progression of inserting more "story" elements into games. For me, something is lost when the tilty-trap swings more in that direction away from the focus on technical player skill. My partner & I have always rolled our eyes at the narrative cut-scenes in real-time strategy games, as another example. But I think we're in the minority, as it's something I've been fairly well exhausted at debating with people over the years -- and probably more than one guest we've had on Wandering DMs has said things like "RPGs aren't about the gameplay, it's about the stories we make with our friends", which I guess I have to respect, but feel completely different about.


Advancement in Classic D&D

Graph trending up

We frequently marvel at how sketchy the advice was in Original D&D (and other early editions) was for the number of monsters, amount of treasure, and expected rate of PC advancement in the dungeons.

There are a few semi-secondary sources that give estimates for advancement rates -- and it's rather remarkable how widely they differ. This is even though they all date from a time post-OD&D-Supplement-I, when in they're all using basically the same monster XP chart and treasure tables.

Gygax in The Strategic Review Vol. 2, #2, p. 23 (1976)

It is reasonable to calculate that if a fair player takes part in 50 to 75 games in the course of a year he should acquire sufficient experience points to make him about 9th to 11th level, assuming that he manages to survive all that play. The acquisition of successively higher levels will be proportionate to enhanced power and the number of experience points necessary to attain them, so another year of play will by no means mean a doubling of levels but rather the addition of perhaps two or three levels. Using this gauge, it should take four or five years to see 20th level. As BLACKMOOR is the only campaign with a life of five years, and GREYHAWK with a life of four is the second longest running campaign, the most able adventurers should not yet have attained 20th level except in the two named campaigns. To my certain knowledge no player in either BLACKMOOR or GREYHAWK has risen above 14th level.

Note that on average this suggests about 60 games in the first year of play to achieve 10th level (i.e., an average of 6 games/level; but there's no reason to think this is a uniform rate over the ten levels). The data points afterward suggest a subsequent rate of about 2.5 levels gained per year of play. Obviously: that's an enormous number of games by modern standards!

Holmes in Basic D&D, p. 22 (1977)

As a guideline, it should take a group of players from 6 to 12 adventures before any of their characters are able to gain sufficient experience to attain second level. This guidelining will hold true for successive levels. Note that it is assumed that the 6 to 12 adventures are ones in which a fair amount of treasure was brought back — some 10% to 20% of adventures will likely prove relatively profitless for one reason or another.

On average, this works out to 9 adventures per level -- 50% slower than Gygax's general estimate (prior to name level).

Moldvay in B/X, p. B61 (1981)

If no one has reached the 2nd level of experience in three or four adventures, the DM should consider giving more treasure. If most of the players have reached the 3rd level of experience in this time, the DM should consider cutting down the amount of treasure, or increasing the "toughness" of the monsters.

On average, this suggests around 2.5 adventures to gain the first level-up -- over 50% faster than Gygax's general estimate.

Is it surprising how much those estimates vary? The one thing I might point to as a difference is that Gygax's play in OD&D/AD&D awards (some) XP for acquisition of magic items, whereas that's never suggested in the Basic D&D lines. Hypothetically that might explain why the Holmes rate is slower, but certainly not why the Moldvay rate is faster.

Can you think of any other obvious mechanical differences in those rules that would explain that? Which rate best matches your experience at the table? Which best matches your desire as a DM at the table?


The Science of Slime-Splitting

Amoeba fission

Recently on Wandering DMs we had a neat conversation about slime-type monsters in classic D&D. Now, in Original D&D, a couple of those infamous monsters are said to split into smaller slimes if they're hit by any physical weapons (Vol-2, p. 19). For example, the Ochre Jelly: "hits by weaponry or lightning bolts will merely make them into several smaller Ochre Jellies". And likewise the Black Pudding: "It is spread into smaller ones by chops or lightning bolts..." But what should the exact result of that spreading be? Let's compute.

As a model, I'll assume that slimes are roughly spherical, and their hit dice are proportional to their volume, but their damage output is proportional to their surface area (being a bunch of acidic gastric vacuoles on the external membrane or something). A sphere's volume is given by V = 4/3πr³, while surface area is given by S = 4πr², r being the radius, of course.

Say we have a starting "unit slime" with radius r₁ = 1. The formulas above give V₁ = 4.2 and S₁ = 12.5. Now let's say we split it with the total mass being conserved; the volume of each of our split-slimes is half of what we started, that is V₂ = 2.1. Taking the equation 2.1 = 4/3πr³, we can solve in a couple steps of algebra to find r₂ = 0.8, and hence S₂ = 8.0. Now, the ratio of our starting and ending surface areas is 8.0 / 12.5 = 0.64, or 64%.

You can repeat this splitting calculation, but the whole process is proportional, so the surface-area ratio stays fixed at each step -- roughly speaking, the surface area, and hence our presumed damage output, always reduces to approximately two-thirds the value of the prior step.

Let's round off and suggest some parameters for split-up slimes of different types.

Ochre Jelly

  • Level 1 -- 5 HD, 1d6 damage
  • Level 2 -- 2 HD, 1d4 damage
  • Level 3 -- 1 HD, 1d3 damage

Black Pudding

  • Level 1 -- 10 HD, 3d6 damage
  • Level 2 -- 5 HD, 2d6 damage
  • Level 3 -- 2 HD, 1d6+2 damage
  • Level 4 -- 1 HD, 1d6 damage

Note that at any hit-die value, Black Puddings are twice as destructive as Ochre Jellies. I'll assume for mechanical simplicity that the splitting stops at the 1 HD level (hopefully PCs get the clue by then what they're doing isn't helping; maybe at 1 HD one half dies off while the other is at effectively full-strength).

What are the advantages of this scientific approach? Well, I like that splitting slimes is not advantageous to player-characters in terms of total damage output -- the total is actually increasing and making the PCs' situation more dire as they unwittingly chop up slimes. For example: level-1 black pudding does 3d6 damage; two half-puddings do a total of 4d6; four quarter-puddings do a total 4d6+8, and so forth. (Compare to the AD&D rule for ochre jellies where the damage is simply halved, keeping the total the same.)

On the other hand, the slimes will have a slightly harder time scoring hits with their reduced HD values. And for very advanced player behavior, move your fighters in to chop up the black pudding like so, and then withdraw, to make sure the wizard's fireball will be able to wipe out all the little pieces in one shot. If you dare?


Because-Dragons Is a Bad Argument

Dragon holding scales of justice
Is this a hot take?

In the D&D discourse, you'll see a common piece of rhetoric, and it goes like this. DM Alice says, "I don't want to allow X in my games; I think it's unreasonable". And DM Bob calls out Alice like this:

Alice says that she doesn't permit X in her games. But Alice accepts Dragons in her game! So that doesn't make any sense!

I call this the "because-dragons" argument. The next most common variant of this argument is, of course, "because-fireballs".

Here's the thing: The space where this argument usually plays out is in the field of features that a player character can opt to start out with. And, to put it briefly, there's lots of stuff in my fantasy world that I would not want players to have on their side at first level.

I'm not even essentially talking about power issues (although that can be a big factor). I'm talking about the background texture of the milieu where player-characters come from. The classic D&D that I fell in love with -- like the pulp fantasy and horror that inspired it -- is well-described by something like Joseph Campbell's theory of the hero's journey

The Hero's Journey

Note that there's a key separation in the structure between the "Known" world -- the place the hero starts at -- and the "Unknown" world -- the challenging region they travel into, before returning to their initial home.

Whether you're playing this as modern mythology, fable-making, or horror (especially that: and recall that HPL is foremost among the Appendix N authors), the most compelling dynamic is that of player characters coming from a (mostly) completely mundane place, and adventuring into a space of unimaginable terrors. By having the "Known" world rooted in reality, we get to comment on things that might be connected to our own world. We get to explore transformations that may reflect possibilities for the players themselves. We can practice how a normal-person can best respond to scary challenges or setbacks. We can use the liminal space between normal and abnormal to test the boundaries of what it means to be people like us. And casual players can more easily interface with how our games start and begin playing with us, too. 

There's a pulp-fantasy gesture I'm very fond of in which the narrator, the normal-human population, and even the protagonists themselves, are essentially skeptical, and disbelieve that supernatural events are occurring around them. There's a nifty play there about whether that fantastic stuff is even real (and of course: it simultaneously is, in the fiction, and it is not, in the real world). The real magic is indeed "Unknown", maybe constitutionally incomprehensible, to the normal-folk from which PCs originate.

Simply put -- Dragons don't belong in the starting "Known" part of the story. This model of the monomyth only makes sense if they are cordoned off in the "Unknown" part of the world. Same goes for Fireballs. And a whole lot of other stuff in the game. The hero does not get to start with that stuff. It would dismantle the meaning of their hero's journey if they did.

I mean, obviously you can play a totally "wahoo" anything-goes-out-of-the-box game if you want. But that's not where the game originates, it's at odds with the most compelling model of the monomyth, and it's simply not for all (or I'd argue most) players.

So it's not inherently incoherent to say there's a "Known" world of mundane things where PCs are born, and an "Unknown" world of fantastic magic and terrors which is separate from that. In fact, it's arguably the strongest structure for fantastic storytelling.

And therefore the "because-dragons" argument (particularly in terms of the what-can-PCs-start-with-in-my-game question) is an epic failure.

(See also H.G. Wells: Nothing remains interesting if anything can happen.)

Thumbnail image courtesy of Craiyon.


On d6 Ability Checks

One of our Wandering DMs Patrons on our Discord server made a great observation: In AD&D Module WG4, The Forgotten Temple of Tharizdun, at one point Gygax calls for a roll-under-Dexterity-on-4d6 to avoid a net trap. More generally, it's been reported in play at tables run by Gygax and Kuntz that they would commonly call for checks in this fashion to roll 3d6 (you know, the same way you generate abilities in the first place for OD&D), 4d6, or 5d6 for tougher situations. 

Now most of us have probably at least heard of rolling d20 under an ability score as a classic check. Oddly, none of these ability-check methods were ever written into the core rulebooks for either OD&D or AD&D. (It does show up as one of the very last optional suggestions by Moldvay in his Basic D&D rules, 1981.) Was this one of those things that was so fundamental Gary overlooked ever writing it down? Or some other reason?

Anyway, the question was posed as to exactly what the success chances are with this method. Here's the result of a quick Monte Carlo program to estimate them (via C++ code on Github):

Chances to make a roll-under-ability-on-Nd6 check.

On the one hand, I personally like the theoretical elegance of a roll-under-ability-score (using some kind of dice) so very much that I often wish the entire system had been aligned to a roll-under methodology from the start, for every kind of check. 

On the other hand, a top complaint is that this makes ability scores too important in the game, whereas by the OD&D books you can legitimately play PCs with fairly unimpressive scores, because they make so little difference to the play of the game. Additionally, the chances for success are vanishingly small in many cases (less than 10% for scores 3-6 vs. 3d6; 3-8 vs. 4d6; and 3-12 vs. 5d6). As one of our top think-tankers wrote, "At which point why are you even rolling?".

A really short-and-sweet mechanic like this does whet my appetite occasionally. In this case the modifying number of d6s to adjust the difficulty seems neat and clean. Would you consider using a rule like this in your games? Or do you still use the classic roll-d20-under-ability idea?