Re-associating exploration speed

Many rules in OD&D and B/X look very weird on paper, when you approach them as “new rules” that are added to what you consider a typical Dungeons & Dragons system. Giving XP for picking up treasure instead of fighting enemies is perhaps the most famous of them, but there are plenty others, like encumbrance, random encounters, or reaction rolls. But I think the purpose of all of these in a greater exploration system has become fairly well reestablished, and I believe I’ve written quite a bit about all of that already.

But one of the things that to me still stands out among these is the unexpected way in which movement outside of combat is handled. In Basic/Expert, the default movement rate for characters exploring a dungeon is 120 feet per 10 minutes. That’s 12 feet per minute, or about one step every 8 seconds. The rules explain that this doesn’t actually mean characters are moving that slowly. What happens is that the characters are carefully searching their environment and drawing reasonably precise maps. Dungeon has become a fairly generic term for any complex of passages, but I think the original idea of what a dungeon is like was less strolling through a castle and more exploring a cave. While very few dungeons are actually natural caves and most have long been used as regular passages by humanoid inhabitants, cave explorers often only manage to progress 300 to 500 meters per day, or say 1,200 feet. If they are at it for 10 hours per day, that’s 120 feet per hour. Even if the PCs are heavily encumbered and have their speed reduced to a quarter, that’s still faster than cave explorers. So maybe not actually a ridiculously low speed.

But where things start feeling strange is when encumbrance comes into the picture. In B/X, encumbrance reduces your encounter speed from 40 feet per round to 30, 20, and eventually 10 feet. And the same modification is also applied to exploration speed. When you take, on average, one step forward every 8 second, you spend almost the entire time of exploration not actually moving forward at all. Heavy loads slowing your movement to half or even a quarter is somewhat believable (maybe the characters are literally dragging heavy bags of loot behind them). But that also reducing the speed at which you can look and poke at things the same way is a cognitive disconnect. It’s a dissociated mechanic. A party with more heavy gear making slower progress makes sense, but representing this through reduced movement speed doesn’t feel very plausible.

However, B/X already has a small, seemingly mostly forgotten rule, that can be adapted for the purpose. Part of the rules for exploration movement is that after every 5 turns of exploration, the party must rest for 1 turn or the characters suffer a -1 penalty to hit and damage from exhaustion. Of the eight retroclones I have, only one carried over this rule. It just seems pretty pointless when you can assume characters are already getting sufficient rest for their legs during the regular exploration turn. And maybe people are right to throw this one out, but I think it’s a great place to apply penalties for encumbrance during exploration instead of reducing speed.

Instead of reducing the movement rate during an exploration turn  to 90 or 60 feet, you can instead increase the rate for required rest to resting for one turn after every 3 turns or every 1 turn of exploration. This seems like a huge decrease of time actually spend on making progress, but because of how the math works out, this system actually makes parties progress somewhat faster than under the default rules. Which is fine with me. Numbers in D&D have never been an exact science anyway and are always simplified approximation. Being 10% faster than by the book isn’t going to break anything. But I feel that this change makes it much easier for players to intuitively grasp why their characters are making slower progress with heavy loads and don’t have to accept it as something that just is because the rules say so.

Return of the Mapper for online games?

Have you heard the good message of our savior Gus L? I learned entirely by accident that he didn’t stop writing RPG stuff but instead has been sharing new stuff on his new site All Dead Generations for the past three years. All the stuff on the site is about what he calls Classic Dungeon Crawling, which is basically OD&D and early Basic D&D, and how that style of Dungeon Crawling is an exploration fantasy game and not a combat fantasy game. A fantastic resource that I recommend to everyone, though it comes in hefty chunks that take quite a while to chew on.

After my overall pretty great D&D 5th edition campaign last year, I was throwing the towel on trying to make dungeons work, because I just could not figure out how to make a dungeon an interesting place that is not simply a warehouse for nonsensical puzzles. All the advice I was coming across on that front was “Well, sometimes funhouse dungeons can be fun.”But now, after 20 years as a GM, I finally get dungeons!

I have seen the light!

Dungeon Crawling and exploration in general isn’t just an aspect of an RPG, it’s even more a system of multiple mechanics than I previously had realized. Treating the whole dungeon as one big puzzle that will reveal the safest ways to the best treasures when figured is a great focus draw players engagement with the campaign. Especially when there’s no plot and characters don’t get shiny new toys every time they level up.

Part of solving that puzzle often is to fully grasp the layout of the dungeon and gain the ability to pinpoint the likely locations of possible shortcuts or otherwise completely inaccessible areas. Gus mentions that having players draw the map themselves is particularly bothersome in online games, where the GM can’t peak at a player’s pencil drawn map to spot obvious misunderstandings of his descriptions. (Minor errors in dimensions are desirable though.) But I took a quick look at Roll20 and found that at least in this case, this thing is actually very easy to do.

Roll20 has the paintbrush tool, which also has a shapes tool that draws rectangles by simply clicking and dragging. As a lifelong diehard user of pencils and grid paper, I think this is actually a lot easier and quicker than drawing lines around squares with a pencil. To correct errors, you can just click on one of these shapes and delete it, without any messing around with erasers. Now I’m definitely going to bring back this aspect of the game in my Great River Campaign. At least giving it a trial run. I’ve been told that there isn’t a function like this in Fantasy Grounds, but I’ve never used that myself. Which seems like a shame, since this is something really simple and basic. Though I guess when you do your mapping like this, you might not be bothering with something as fancy as Fantasy Grounds.

Rolling hit points for monsters

As I was delving into the ancient ruins to seek the wisdom of the sages of past ages, I came upon this nice little gem on Planet Algol: Non-randomized Monster Hit Points is the F’ing Devil. The unknown author (seriously, there’s no name anywhere on the site) makes a point that you really should roll the hit dice for monsters and NPCs the players might fight an not just assume the average, as it has a real impact on customizing individual opponents. Would players ever notice the difference between a 2d8 creature with 8 hp and an otherwise identical one with 11 hp? Probably not. But they very much would notice the difference between a 3 hp and a 15 hp one.

A note  is being made about perhaps rolling only one die and multiplying the result by the number of die, to make more extreme results more common than under the normal distribution you get from rolling and adding up multiple dice. But I was also curious about the results you would be getting from rolling hit points normally for every opponent and so I pulled up AnyDice to check.

The added up results of multiple die rolls are a classical of a normal distribution. The classic bell curve. A typical way to compare and interpret the distributions of these curves is by using the Standard Deviations as reference points. I once learned how to calculate standard deviations and also understood the reason why they are typically used instead of any other arbitrary reference lines. I’ve forgotten all of that years ago, but I am going to use them anway. (And it turns out AnyDice can just tell you that number, spring me the need to manually crunch numbers for other reference values.) The only thing that’s really important to know is that 68% of all results will lie within 1 SD of the median value (the line between the lower 50% and the upper 50% of all cases), and 96% of all results within 2 SD.

Source

Since almost all creatures use d8 for hit points, I’m going to do the whole thing only for d8s. Obviously the spread will be somewhat smaller for smaller Hit Dice, and larger for larger ones, but the pattern remains the same.

HD -2 SD -1 SD +0 SD
+1 SD +2 SD
2d8 3 6 9 12 15
3d8 6 10 14 17 21
4d8 9 13 18 23 27
5d8 12 17 23 28 33
6d8 16 21 27 33 38
7d8 19 25 32 38 44
8d8 23 30 36 42 49
9d8 27 34 41 47 54

Now how to read this table for the not statistically trained? What this means is that 68% of all results you get will be between the -1 SD and the +1 SD columns. 96% of all results you get will be between the -2 SD and the +2 SD columns. Or in other words, only 2% of results will be smaller than the left column and only 2% larger than the right column.

Here’s the same data a bit more condensed, showing the range of hit points for 68% of the creatures if you roll their hp.

HD +/-1 SD +/-2 SD
2d8 6 to 12 3 to 15
3d8 10 to 17 6 to 21
4d8 13 to 23 9 to 27
5d8 17 to 28 12 to 33
6d8 21 to 33 16 to 38
7d8 25 to 38 19 to 44
8d8 30 to 42 23 to 49
9d8 34 to 47 27 to 54

Here the left column is the range you will see for 68% of your creatures, and the right column what you’ll see for 96% of your creatures. Results outside the range of the right column will occasionally happen, but will really be quite rare. As the number of dice goes up, the spread of the result will be come relatively narrower. The difference between 34 and 47 really is not that big and players might not notice. But the vast majority of enemies that will be fought in groups will have much lower number of Hit Dice, especially those in larger groups. Going from 6 to 12 means double the amount of hit points for 2d8 HD opponents, and when you deal 3 or 4 damage, that makes a real difference. And that’s only for the 68% group. A 2d8 creature with 2-3 or 15-16 hp will be rare, but still account for about 5% of individuals each. In a group of 10, you’d expect to see one of these outliers.

So yeah, I agree with the anonymous author. Rolling the hit points for every opponent individually seems very much worthwhile when you have a game with few fixed bonuses to the dice roll and PCs commonly dealing single digit damage.

A take on Reaction Rolls and the Charisma modifier anomaly

The Basic/Expert rules are the system that keeps on giving. At only 121 pages (of which 43 are monster and treasure descriptions), they would make a pretty thin rulebook and still I keep coming back to them to reread various sections over and over. I’ve seen people considering the ambiguities and unfinished nature of some rules to be a virtue many times, but I don’t consider it good design or even intentional. I’m quite certain that Moldvay and Cook mostly had specific rulings in mind but were not aware that they didn’t sufficiently communicate them in a clear way, and possibly in some cases simply copied things that Gygax had written before without really understanding how it’s supposed to work either. I’m usually not too hard on this, giving them some leeway considering that they had no real reference for what they were doing and making things up as they went. And with rules that into only 78 pages, filling in the gaps is not that much amount of work.

One section I was going over again recently are the mechanics for Reaction Rolls. The reaction roll is used to determine how randomly encountered creatures react to the party, if their behavior isn’t already obvious given their nature and circumstances of their encounter. Creatures like zombies always attack everything they encounter. Goblins always attack when they encounter dwarves. And if you have the party trying to sneak into a guarded enemy stronghold and they run into a guard patrol, the attitude of the guards is also obvious. The Reaction Roll is for situations in which the reaction of the creatures could be anything. But there’s still a lot of ambiguity left. What are you supposed to do with “Uncertain, monster confused”, which is the most likely of all reactions? How is it different from “No attack, monster leaves or considers offers”? The reaction roll is also modified by a character’s Charisma score. But whose charisma score? And if the Charisma score is 13 or higher, the result of “Immediate attack” is impossible to happen. So after pondering the issues over several days, I came up with the following procedure. I believe it mostly just fills in some blanks without really changing anything that is printed on the pages.

Beginning an Encounter

An encounter can start in two ways: The party enters an area in which monsters are already present, or the GM made a roll for Wandering Monsters for that turn. In the order of events for every turn (10 minutes of dungeon exploration) the first step is rolling for wandering monsters. The second step is “moving, entering rooms, listening at doors, and searching the environment”. Dealing with monsters comes as the third step. I think this order is significant because it can mean that wandering monsters can stumble into a room while the party is in the process of searching it. The random encounter is something that happens within the turn, not between turns.

Surprise

If the party and monsters encounter each other, the next steps are determining the distance at which they can become aware of each other, and rolling for surprise. These two steps happen basically at the same time and it doesn’t appear to matter which of the two rolls you make first. But I think it’s actually more convenient to roll surprise first and determine the distance after.

To roll for surprise, both the party and the monsters roll a d6. By default, a 1 or 2 means that they are surprised, while a 3 to 6 means that they are not. Two d6s allow for 36 possible results that cover four different outcomes.

Odds Outcome
4 in 36 Both sides are surprised.
8 in 36 Party is surprised, monsters are not.
8 in 36 Monsters are surprised, party is not.
16 in 36 Neither side is surprised.

Some monsters have a special ability that makes the party getting surprised by them on a roll of 1 to 3 or even 1 to 4, which significantly changes the odds to get the jump on the party in their favor. (A monster ability that modifies the party’s roll instead of their own roll isn’t very elegant, but it’s probably the least complicated way to get the desired result.)

The results of both sides being surprised and neither side being surprised are basically identical. However, I’ve seen a rule somewhere, and to my actual surprised it’s not in B/X, that in the case of both sides being surprised, the encounter distance should be half of what it would be in the other three outcomes. I really like it and so I’m mentioning it here anyway. This is also why I would make the roll for the encounter distance after the roll for surprise. Inside a dungeon, the distance is 2d6 x 10 feet, outdoors it’s 4d6 x 10 yards (or 4d6 x 30 feet, because we really don’t need two different units of measurement).

Something that surprised me coming from later editions is that the rules for surprise don’t really seem to take into account that one side or the other could by lying in ambush, or have time to quickly set one up. However, the Expert rules state that a group of three or more gains surprise outdoors they could be set up to have surrounded the other side. Maybe the idea is that even when you see a light at the next corner or hear footsteps approaching, there just isn’t enough time to set a proper ambush indoors. But I am a big fan of sneakiness myself, and I think it should absolutely be possible for players to avoid getting noticed by the wandering monsters, or quietly retreat from an area that has unaware monsters inside.

The rules as they are written only state that “those not surprised my move and attack the first round, and the surprised enemy may not”. I think the whole game becomes much more interesting if the side that has surprise can use its turn during that first round to back away without the surprised side becoming aware of them. Not only can it be a great opportunity for fun shenangians on the players’ side, it can also be interesting to have monsters stalking them in secret and wait for a good opportunity to strike.

Reaction

After surprise and distance have been determined, the sixth step is the Reaction Roll. As I mentioned earlier, the reaction roll is modified by Charisma. But whose Charisma actually? I long assumed that it would be the character who is walking at the head of the column or perhaps the party member with the highest Charisma, but that never really felt right since there is no indication either way.

The new idea I got recently, and which is the reason for this entire post, is that the reaction modifier for high or low Charisma only applies if a PC has the opportunity to talk to the monsters before a fight breaks out. If the monsters are surprised but the party is not, one of the PCs can hail the monsters and they make a reaction roll modified by the PC’s Charisma. If both or neither side are surprised and the party wins initiative for the first round of the encounter, the players also have an opportunity to hail the other group.

There is also the possibility that the monsters surprise the party or they win initiative, and their reaction is “Uncertain, monster confused”, which is the most likely result for an unmodified 2d6 roll. I’ve seen some retroclones rephrase this result as the monsters waiting to see what happens, which I think is a great interpretation. What you get is the monsters simply doing nothing for now. Then when it’s the party’s turn and the party is aware of the monsters, the players have another opportunity to hail them. At which point you could make a second reaction roll, but this time modified by the respective character’s Charisma.

And there’s actually something in the order of events for each exploration turn that supports that. Step six is making a reaction roll, but step seven, the resolution of the reaction, says “If both sides are willing to talk , the DM rolls for monster reactions and initiative, as necessary.” Making two reaction rolls is already written into the rules as they were printed. And I think it makes perfect sense to have a character’s Charisma modify a reaction roll only in those cases where that character is talking to the other groups. In situations where the monsters spot the party but the party is not aware of them, I think the reaction roll should be done without any modifiers at all. It’s of course also possible that the players might think of something so convincing that no reaction roll is necessary at all. If for example they encounter a group of guards and know the password to identify themselves as people who have permission to be in the place, then making a reaction roll can become moot. In the same way, if the party has surprised and decides to attack immediately and ask questions later, no reaction roll is necessary either. (Though a morale check might be.)

The Charisma Modifier Anomaly

Unlike in AD&D, the modifiers to various things based on the various ability scores are quite consistent in Basic. An 18 in Strength gives you a +3 bonus to melee attack rolls and melee damage, an 18 in Dexterity gives you a +3 bonus to ranged attack rolls and Armor Class, and an 18 in Constitution gives you a +3 bonus when rolling your hit points for each level. But Charisma stands out. An 18 in Charisma gives you only a +2 bonus to Reaction rolls instead of +3, and a 16 or 17 only a +1 bonus instead of +2. Some retroclones fix this by applying the same modifiers to all six ability scores, and I actually did this myself in the past. But I now think that this inconsistency is not an oversight but actually a deliberate choice.

The modifier in question is not a generic modifier to Charisma rolls, but specifically an “Adjustment to Reactions”. Reaction rolls are its only intended application (though this includes retainer hiring reactions for which the following calculations apply equally). The Reaction roll is 2d6, and the Reaction table lists results from 2 to 12. The “Immediate attack” result can only happen on a 2 (or lower, one presumes), and the “Enthusiastic friendship” result happens on a 12 (or higher). If you get a +1 bonus to the roll, a result of 2 becomes already impossible. You can’t go lower than 3 and get “Hostile, possible attack”. Which is one more argument why some Reaction rolls should be done without applying Charisma modifiers. But not only that, the 2d6 also give us a bell curve and shifting a bell curve sideways results in often very significant changes in the odds for any given value. When you get a +3 bonus to the Reaction roll, even the hostile result only has a probability  of 3%. Pretty much anything would be somewhat friendly if you’d happen to have someone with 18 Charisma doing the talking for the group.

But I think the +3 bonus from an 18 is not even the main reason for why the modifiers are different for Charisma. The chance for any given Character to get a randomly rolled 18 on 3d6 is under 0.5%. In a group of four characters, that’s still below a 2% chance for any of the characters to have an 18, and that player might not even want to do all the talking with everything they run into. It’s an unlikely scenario. But the chance for any character to randomly roll a Charisma score of 16, 17, or 18 is almost 5%, and getting someone in a party of four with a 16 or better is 17%. And a bonus of +2 to Reaction rolls is still really big. At +2, you have a 17% chance for a friendly reaction and only an 8% for a hostile one. With a 42% chance for monsters to negotiate. That frankly doesn’t sound particularly fun to me. Having the odds for this scenario being only 2% for any given party of four instead of 17% seems a very sensible change to me, even if it breaks the beautiful symmetry of ability score modifiers.

Prime Requisites are pointless

The original D&D edition, AD&D, and Basic all had the Prime Requisite mechanic, in which all classes have one main ability score that affects the amount of XP they get. It’s a modifier that gets applied to all XP a character gets before they are added to the character’s XP total. In B/X (where I will be taking all further numbers from) the modifier ranges from -20% for a score of 5 or lower, to +10% for a 16 or higher. Which sounds quite significant when you put it like that, but actually makes a much smaller difference than you might expect, because of the way XP requirements to reaching the next level increase.

The way it’s supposed to be done is that the GM announces the amount of XP every player gets, and the players have to remember to apply their relevant modifier to that number before adding it to their total. (I don’t exactly have high trust in this.) Since the players might encounter various magical effects that increase or decrease their ability scores, and potentially change their XP modifier, I can see why this approach was chosen, instead of having five different columns for XP needed by each class based on the prime requisite score. But to make the comparison easier, I did just that with the XP requirements for fighters. Because adding and subtracting percentages changes the outcome based on the order of operations, a -20% to all XP gained translates to the character requiring 125% the amount of XP to reach any given level. And a +10% bonus to all gained XP means a requirement of 91% the XP to reach the same level.

How does this translate to characters advancing through levels faster or slower? Of course, a character with a very high prime requisite score will reach Nth level before a character with a very low score. But how big is that advantage in the long run?

  • At 10,000 XP, a Fighter with a -20% penalty will have reached 4th level, and a Fighter with a +10% bonus will still be 4th level.
  • At 50,000 XP, a Fighter with a -20% penalty will have reached 5th level, and a Fighter with a +10% bonus will still be 5th level.
  • At 100,000 XP, a Fighter with a -20% penalty will have reached 7th level, and a Fighter with a +10% bonus will still be 7th level.
  • At 500,000 XP, a Fighter with a -20% penalty will have reached 10th level, and a Fighter with a +10% bonus will be ahead at 11th level.

It is only at the point where the GM has awarded all characters 72,000 XP and a Fighter with no modifier has reached 13th level that there’s an actual gap to Fighters with a -20% penalty, who are still at 11th level. And that’s for the extreme cases where a player with a Strength of 5 or lower decides to play a Fighter anyway for shits and giggles. Such characters being played up to 11th level probably isn’t going to happen in a terribly high number of campaigns. If we narrow the scope to only penalties of -10% and bonuses of +10%, the effect becomes even significantly smaller.

It’s even more marginal in AD&D, where characters can’t have any penalties and it’s only the default XP or +10%.

This does not seem like something that is worth accounting for. Having players with high or low prime requisites remember to apply the modifier every time they get XP does not seem worth the near undetectable difference in results to me. If you have two characters with the same class start at the same point, then yes, sometimes one player might announce that he reached a new level before the other player. But if either of those two characters misses out on a single session, or gets disabled and gains no XP in one session,, that pattern will already be completely out of whack anyway.

In my opinion, prime requisites make too little impact to be worth bothering with. I’ve come around on my earlier opinion that all classes should just use the Fighter XP requirements because the level difference between a Thief and a Wizard with the same XP really is quite substantial. (A wizard needs +100% the amount of XP that a Thief needs!) But prime requisites is something I threw out right when I started running B/X games, and that  under closer statistical observation, I still see no reason to bring back.