Chainmail magic: Spell Complexity, Counter spell, and more oddities

Chainmail* has several interesting ideas that have been "lost" in the transition to D&D. Studying them is fun and can provide many ideas for your D&Dish games. Today, we tackle magic, in three parts: Spell Complexity, Counter spell, and other curiosities.

[*affiliate link]

Spell Complexity

Spell Complexity is an optional rule where "each listed spell has a complexity value, and this value indicates how difficult it is to use such spell. [...] In addition, there may be a delay in the effect of the spell, or it may be totally negated due to some minor error or distraction. The table below gives the scores necessary for immediate, deferred (1 turn), and negated spell effects by the various levels of magic-users.".

In other words:

- Roll 2d6. Subtract spell level. Add half your level, round up (this is an approximation, CM units have names instead of levels).

- 8 or more means the spell is cast immediately. 6-7 means it is delayed for one turn. 5 means the spell fails. 

While I have written my own roll-to-cast rule for B/X, I must admit I'm enthralled by this one, simply because of the spell delay aspect. It adds another layer of excitement/tension and choice/tactics to everyone on the battlefield.

Now spell interruption is not only about initiative, but about a series of choices on both sides of the battle.

BTW, the book won't tell you what happens if you roll lower than 5; I first assumed the spell is lost for the day, but it could also be a spell mishap, etc. Look at the post I mentioned for more ideas. But, as mentioned in the comments, the table probably indicates that 5 or less means the spell fails. The notation is horrible but supposedly it is common in wargaming at the time.

Counter spell

"The stronger magician can successfully cast a counter-spell with a two dice score of 7 or better, while a weaker magician needs a score of 8, 9, 10 or 11, depending on his relative strength. A counter-spell fully occupies a magician's powers." 

In other words... you could employ a similar dice roll as the one describe above, adding your level and subtracting your opponent's level (half-level would be more precise, but I'd favor simplicity here).

CM does not delve into further detail; I assume the spell that is successfully countered is negated. I'm unsure if only delayed spells can be countered, but it would be fun if your delay allowed another magician to not only counter your spell but also cast a spell against you, etc.

Again, this adds another layer of tension and tactics to the game.

Other curiosities

"Wizards can handle magical weaponry. [...] Wizards can become invisible and remain so until they attack, they con see in darkness, they affect friendly and enemy morale as do Super Heroes [...]. Wizards are themselves impervious to normal missile fire but if they are struck by a missile from an enemy Wizard they must score 7 or better with two to survive."

They seems very powerful!

Wizards are also artillery. They can throw fireballs and lightning bolts (with effects similar to guns and catapults), which are not spells, so presumably they don't "roll to cast" and never run out. I like this approach and I added an "arcane artillery" feat to my Old School Feats.

A wizard - the highest level a magic-user can get - has only 6-7 spells. If we count fireballs, lighting bolts, and in visibility, we are not very far from one spell per level, which I like.

Also notice the lack of "Vancian" casting. No memorization. You just have a few spells that you can cast over and over until you fail.

Overall, I really like Chainmail magic. It is somewhat simpler and at the same time has more tactical depth than B/X, without getting to AD&D levels of complexity.

It doesn't require memorization, material components or specific casting times; the spells can be cast more often, but also can be delayed and countered. This seems to me as a superior alternative as it is more exciting than a list of requirements.

A B/X conversion?

How about 10+ means immediate casting, 5+ means delayed casting, and less than that you fail or lose the spell? This makes MUs lose some of their speed but not their power. Seems good for starting MUs, but as always they become too powerful at higher levels. As always, some fine-tuning is needed.

Old school dice pools

So, I just had a fast combat/mass combat idea for D&D, probably from  Chainmail or Delta's blog:

Roll 1d6/level for fighters, half as much for clerics, 1/3 for MUs.

1 misses, 2-5 hit/miss depending on AC, 6 always hits. 

Monsters only need one hit per HD and we don't even need d20s. 

The idea is making combat against dozens of opponents a bit quicker.

But come to think of it, it could be pushed into an entire system. Let's see.

Duels

Two 9-HD fighters facing off would each roll 9d6 and cause an average of 3 hits per round (assuming they hit on a 5-6), so combat would be a bit quicker than, say, B/X.

Ranged combat

Both in real life and D&D, ranged combat is not usually as efficient as mêlée combat. Maybe adding 1 or 2 to AC is enough. To avoid treating an archer like a machine gun, you can rule "missed" shots are time spent in aiming, drawing, etc., and only "hits" or 1s waste arrows.

Against a single target, maybe all damage comes from a carefully aimed single arrow; so a very powerful fighter with a magic arrow could kill a dragon immediately, but this is very rare.

Weapons

Certainly there is some nuance lost here. Let's assume everyone is using a single-handed weapon. 2H weapons might add a dice, while maces may remove a point of AC, etc.

Turn Undead

Cleric rolls 2d6/level. 

Rolling 2-5 turns one HD of undead, 6 damages them. You can alter these numbers to make the cleric more or less powerful, or maybe make turn undead a spell (see below).

Spells

Casters have 2d6/level "magic dice" per day. 

When casting a fireball, it works identically as a fighter's attack, but any 6s you roll are removed from your pool until the next rest. 

(I think I got this idea from Necropraxis).

This fixes a number of fireball problems I usually have.

Same works for curing wounds.

But what about spells that deal no damage? Maybe we could still keep the "roll to cast" and "magic dice" aspects. a 4-6 counts as a success; a 1st level spell requires only one success to function, etc.

You can use several dice to cast a 1st level spell, so you can be sure it succeeds in the first try, but that way you'll also roll more 6s and spend more dice.

Skills

Let's use "hear noise" as an example. Non-thieves have 1-in-6 chances, thieves start with 2-in-6.

So let's say a normal PC rolls 1d6, but a thief adds 1d6/level. Rolling a single 6 means success, so the thief start with 30.5% chance. By level 10, he rolls 11d6, with a 85% chance of success. He won't get to 99% until level 19-20 or so, which is nice, so there is always some chance of failure.

Maybe multiple 6s mean extraordinary success, and rolling all 1s means disaster (e.g., falling from a climb or getting caught in a trap).

Backstabbing is easy; a thief simply attacks as a fighter while backstabbing, and maybe lowers the AC by one if you want them to be really deadly.

Saves

Saves can work similarly to skills. Everyone gets 1d6 plus 1d6/level. 

Notice that the progression from 30% to 85% between level 1 and 10 is quite fitting. You can give fighters, dwarves, paladins etc. an extra die or two.

You do not usually "save" against damage; treat this like an attack against AC (see below).

HP

There is no more HP, only "hits". To make things a bit softer, I'd give each PC one hit PLUS level for fighters, level/2 for clerics etc.

Maybe you could do the same for monsters so that a 1 HD monster has 2 hits and so on. 

AC

AC now is 2 (unarmored) to 6 (plate+shield). 

If you want magic armor etc. you could go even higher, but then you'd need special rules. For example, each time you roll a 6 you can roll again and add 5 to get a result from 6 to 11.

In conclusion...

Well, if you like dice pools, you can see that you might was well play old school D&D with them and a little conversion. But you'd lose some nuance in ability scores, weapons, etc. Maybe just sticking to the d20 is easier.

Still, we have some nifty systems for mass combat, and maybe skills, spells and saves, to experiment with.

AD&D 2e reaction table

The AD&D 2e reaction table is... interesting:

Compare it to the BECMI reaction table, discussed here.

The tables are different for several reasons, but the main distinction is that the AD&D 2e table requires you to check the player characters' attitude before finding out how the monster behaves, while every other D&D table I can remember goes the opposite way: first consider the die roll, then check how the monsters behave.

Of course, in practice you can always ask how the PC's react first (or ignore the rection roll altogether, etc.). But I think it would be better to rely on initiative here - if the PC's have the initiative, they can choose to show they're friendly before the monsters decide how to react, which would certainly give them some advantage in the reaction roll.

If they LOSE initiative, the monsters "react" first - but if they are uncertain, this gives the PC's another chance to make a peaceful gesture, etc.

Another interesting aspect of the 2e table is that it can result in flight. This makes some sense as the table is affected by morale modifiers. A curious idea! Should scared monsters be friendlier? It makes some sense if they are intelligent, otherwise they should just run away if they can (which is the case if PCs are hostile).

Unfortunately, the actual morale score is irrelevant here; a monster with morale 18 and other with morale 10 are both as likely to flight or be hostile. 

Curiously, since chaotic creatures have -1 to morale checks for some reason (they are probably more cowardly and less organized), they are also more likely to be friendly, which is a mistake IMO.

Overall, the 2e table is not any clearer or better than other tables, but it has several advantages we can use - and a few disadvantages I'd like to change.

It feels too friendly to "indifferent" PCs, do not contain immediate attacks, and is organized in a 4x19 grid instead of the usual 5 entries. It also seems to lack a "cautious" column that should be the default for PCs, with equal chances of friendliness and hostility.

Maybe my ideal 2d10 table would be smaller, containing a single column instead of a grid. Give the PCs a -1 if they manage to show they're friendly before you roll (e.g., if they win initiative); let he "speaker" or "leader" make any kind of Charisma "check" you feel appropriate to change this to -2 [simply including the charisma modifier feels too extreme, IMO; it would make everyone your friend]. 

If they are hostile or attack, roll with +1 to +2 (it is unlikely you need to roll after the PCs attack).

2–3. Friendly

4–6. Positive

7–10. Curious

11–13. Indifferent

14–16. Suspicious

17–18. Negative

19–20. Hostile (fight or flight - morale check)

As you can see, I added morale only to the last entry. But you can also use it whenever intelligent NPCs feel threatened or unable to escape, to see if they negotiate or surrender.

This is not much better than the original 2d6 table. Except that 2d10 allows you some extra room to give +2 and -2 modifiers. Maybe a simpler version would be better:

2–4. Friendly 

5–7. Positive, indifferent

8–12. Cautious curiosity  

13–16. Negative, suspicious, aggressive

17–20. Hostile (fight or flight - morale check if needed)

But then again, I've written about this before... more than once! 

So I'll leave this as a small post about 2e reaction, and point you to some older posts about reaction rolls in general:

https://methodsetmadness.blogspot.com/2023/05/reaction-rolls-in-practice-osr.html

https://methodsetmadness.blogspot.com/2022/10/a-d20-reaction-check-osr.html

RPGs vs. Wargames - Zooming in and out

I have written about this before. Today I'm not discussing if RPGs are wargames or not. I'll just notice that there's a tension between the wargame and RPG perspectives, and will discuss how it manifests in Chainmail (wargame) and D&D (RPG).

The main difference is one of scope:

- Wargames are (traditionally, although there are exceptions) focused on battles between dozens to thousands of people; each player controls many people.

- In RPGs (traditionally, although there are exceptions), each player (except the GM) plays a single character/"role".

D&D was spawned from Chainmail (in OD&D, Chainmail appears as required material), among other games, and we can see the shift in focus as the game progresses. There is a "zooming in" of sorts.

Here are a few examples.

Alignment

Originally, alignment was about factions/teams. In modern D&D it is linked to personal philosophy, outlook, and behaviors. This shift creates some confusion and is discussed here.

Weapons

Chainmail had very important weapon versus armor rules that couldn't be ignored. Maces are better against plate, and daggers are a lot better against unarmored people. There are magic weapons, but not many details, you can get a bonus due to a generic "magic sword" or "magic arrow", for example.

When you get to D&D, the focus starts shifting to individual weapons. Magic weapons get more detailed (flaming swords, then vorpal swords, mace of disruption, etc.) and swords get deeper personalities and stats of their own. This tendency will continue through editions, with an ever-growing number of singular magic weapons.

The weapon versus armor table, on the other hand, is included in AD&D but often ignored in actual play (even by Gygax). In 2e, it gets simplified, and from 3e onward is nearly forgotten. The individual weapon is more important than weapon type. 

Ability scores and other stats

Chainmail does not use ability scores or many individual stats. Most creatures are defined by type/HD, AC, and attacks. In  OD&D, ability scores are present but not as important, and there are cases when Dexterity 7 is equal to Dexterity 14 in most circumstances; class and level are way more important. But soon "ability checks" become popular, and ability tables gain more detail; there is an effort to make each single point important. In modern (post-2000) D&D, ability scores are almost as important as class and level.

One interesting anecdote is how some classic D&D characters get names that are jokes/puns, simple anagrams of their player's names, or derived from class and level - the famous "Melf" is a "Male elf" abbreviation. Compare this to Drizzt, for example; a rebel drow that is opposite to whatever drow originally represented.

Hit points and level

In Chainmail, creatures are defeated or not with one or a few "hits". Hit points are created precisely because players get attached to their characters. This causes a "hit point inflation" eventually. Individual advancement, which doesn't quite exist in Chainmail, becomes an important focus of the game.

Dungeons and the battlefield

Wargames are often set in open spaces. Tight dungeons require a tighter focus. In old school D&D, this tension is often resolved by giving weapon range and movement different meaning indoors and outdoors (from feet to yards IIRC), which I find to be an elegant solution, but it later editions simplify things to make them equal despite the environment - often assuming that you're in tight environments anyway and even focusing on "grids" and "squares", especially in 4e.

Large battles

Large battles are assumed in Chainmail. In early D&D, the fighter gets some tools to fight hordes of weak creatures; this is expected. In modern D&D, this becomes somewhat of an special case. By 4e, you get "minion" rules to facilitate large battles. 

Individual monsters

In modern D&D, even lowly monster get endless variations, so that these creatures can also be individuals. The stat-block get bigger. By 3e, creatures have ability scores of their own. You also get more detailed rules on how to interact with them on an individual basis, maybe negotiating and so on. Most intelligent monster will have names, personalities and particular interests, which were not as relevant in old school D&D.

In conclusion

Wargames and RPGs are not necessarily incompatible, and some believe that RPGs are a subset of wargames. 

I do believe some "hybrid forms" or tools that allow you to "zoom in and out" are fun and will give you that "Appendix N" feel; Conan is sometimes in dungeons and single combat, and sometimes fighting or ruling over hordes and kingdoms.

Realizing there is a tension between the two perspectives may be useful to choose what rules to apply to your own games.

Additional reading:

https://methodsetmadness.blogspot.com/2024/02/wargames-storygames-and-rpgs.html

https://methodsetmadness.blogspot.com/2024/04/character-death-in-rpgs-war-games-and.html

https://methodsetmadness.blogspot.com/2023/06/weapon-versus-armor-from-ad-to-bx.html

https://methodsetmadness.blogspot.com/2017/03/does-d-require-miniatures-3e-versus-4e.html

https://methodsetmadness.blogspot.com/2025/03/brief-mass-combat-idea.html

https://methodsetmadness.blogspot.com/2015/03/on-alignment-part-i-alignment-origins.html

Brief mass combat idea

Here is a brief mass combat idea meant for old school D&D or OSR games. I'm using ascending AC in my examples because that's what I use in my games.

Here is the idea:

10 1st level fighters count as a single fighter with a +10 attack bonus until the end of the round.

They attack as one. They deal one die of damage (say, 1d8 if they're using swords).

They add one point of damage for each point over the AC (if using ascending AC).

By Dean Spencer

Let's say 10 bandits are attacking your 5th-level  PC, who has AC 17. They roll 9. Adding a +10 bonus, this means 19, two points more than needed to hit. They deal 1d8+2 damage.

The best part about this idea is how it vastly simplifies things.

If you decide only 4 or 6 fighters can attack the PC at a time, just reduce the bonus to +4 or +6.

If the PC slays a couple of bandits, reduce the bonus to +8. And so on.

In some cases, you can just add up all HD. If your PC is attacked by a 3rd level fighter and 3 bandits, they can make one single attack with +6.

It also makes goblins, etc., dangerous though all levels. If your PC in magical plate and shield gets attacked by ten goblins, it is VERY LIKELY that ate least one of them will get a good stab!

This will probably be useful when PCs have multiple henchmen too. One roll, period.

Is this similar to actually rolling each attack individually? Well, it varies a lot depending on AC, number of foes, etc. Apparently, the bigger the group, the smaller the damage each individual adds (which might be explained by fewer people being able to attack at the same time). 

Let's try with six goblins attacking a fighter in plate [AC 16], using B/X (or OSE) rules. The usual damage per round (DPR) would be around 5.25. With my proposed rule, it would be about 4.4. 

If the fighter is unarmored, DPR is also similar (11.55 versus 9.78, more or less). Not bad.

And if the fighter has plate, armor, and some magic bonus to AC? Let's say AC 20? An extreme case, but... Then damage doubles from about 1.05 to 2.28. So the rule works as intended!

(These numbers were calculated with the help of AI... let me know if they're wrong!)

I probably wouldn't use such a rule if you're fighting a couple of giants, for example; just for low-level foes. Likewise, allowing 15 goblins to attack you at once sounds unwieldy; I'd keep the limit at 10 for now, and you ever fight 20 goblins at once they cannot attack you as a single unit (treat them as two groups).

I probably COULD use this idea for huge mass battles, just adding a few zeroes when needed.

Say, a force of 90 knights clash with 50 enemy knights. The 90 knights attack with a +9 bonus, etc. They deal 1d8 damage (or whatever) plus the margin of success. Then just multiply damage (or casualties) per 10, and reduce the opposing force equally.

I haven't played-tested this. But I have a good feeling about it...

Additional reading:

https://methodsetmadness.blogspot.com/2023/02/the-hd-game.html

I want LESS!

Most of my time playing and reading RPGs has been ruled by the “undisciplined pursuit of more.”

I played several RPGs and took pride in trying new ones. I favored "universal" systems where I could create endlessly detailed PCs and do anything I wanted. I also collected monster manuals for my D&D-ish needs.

This process has been somewhat useful in helping me discover my tastes and needs.

However, there has also been much waste. I read only a fraction of the RPGs I buy and play an even smaller fraction of the RPGs I read. Nowadays, I'm embracing "the disciplined pursuit of less."

In other words, I want less: fewer monsters, fewer spells, fewer magic items, fewer stats, and simpler systems.

This partly reflects my appreciation for minimalism, but it goes beyond that. I believe that having fewer elements makes each one more important and meaningful.

While having a multitude of monsters is fun, each Monster Manual contains more creatures than entire worlds like Middle-earth, Barsoom, Lankhmar, or the Hyborian Age (not to mention most horror and sci-fi settings). It becomes virtually impossible for PCs to understand each individual monster with any depth.

Take dragons, for example. The dragons of mythology and literature are often unique individuals, like Smaug, Fafnir, Tiamat, Drogon. Each is distinct and memorable. But the 2e MM (my favorite!) has about more than a dozen dragon types. If a D&D party sees Smaug, it is just another red dragon (they don't even need to interact to know that he is chaotic, since he is red; but this is another issue).

[Another thing I've been considering is how adding more monsters to a game doesn't make it any different from "standard" D&D, but replacing existing monsters creates a completely new kind of setting. Take Curse of Strahd, for example: it includes few "demihumans," and even the elves are distinct from the familiar elves we're used to. This seems to hold true for most of my favorite settings and modules, and I think I might never run an adventure containing orcs again.]

Magic items are the same: Excalibur or Stormbringer are memorable, and so is Sting. In D&D, a first-level party often has dozens of magic items. Eventually, they discard some of them as they reach higher levels. This abundance devalues magic items and magic in general.

I feel the same way about rules.

I’ve run a few 5e campaigns. 5e is a more "complete" game than B/X. However, it requires ten times the page count to achieve this. So, I’ve been asking myself: is 5e ten times more complete than B/X? And the answer is no. Same goes for AD&D.

[Sure, I could use a one-page RPG. In the end, this ultimately comes down to a matter of taste.]

Spell selection has also been a headache, leading to imbalance and analysis paralysis.

I like customizing characters, but I don’t need dozens of classes and races. I really enjoy the simplicity of being able to say the bandit leader is a "fighter 5" and leaving it at that.

When you have fewer elements, you can connect them more meaningfully. For example, elves resist ghouls. The undead are raised by demons. All aberrations come from other dimensions, while monsters are created by mages. Etc.

And to be honest, this would make way more likely that my players would even REMEMBER most of this stuff.

In short, many of my current issues with D&D could be solved by just having less.

Additional reading:

https://methodsetmadness.blogspot.com/2024/05/unlimited-d-x-limited-d.html

https://methodsetmadness.blogspot.com/2018/01/the-illustrated-war-of-earth-and-sky.html

https://methodsetmadness.blogspot.com/2025/01/magic-item-inflation-in-ad.html

https://methodsetmadness.blogspot.com/2023/10/skeleton-with-bow.html

https://methodsetmadness.blogspot.com/2015/01/minimalism-elegance-and-multipurpose.html

Dead-end mechanics

When I was analyzing the 1e DMG - a project I plan to complete in 2025 - I noticed it has several interesting sub-systems. 

While I prefer simpler games, I can see the value of having interesting detail to your games, no matter how idiosyncratic (for example, AD&D seems obsessed with polearms, while swords do not seem to get the same attention).

There was something bothering me about AD&D and it was not the bits that felt unnecessarily complex. The system felt a bit disjointed and I couldn't quite explain it until I gave it a name: dead-end mechanics.

This is not something specific to AD&D - it can potentially happen in any RPG, and it might be closely related to what makes RPGs unique.

AD&D is a good example only because it has so many moving parts.

Let's try a definition: dead-end mechanics are parts of an RPG system that do not meaningfully interact with other important parts, especially when those other parts are thematically related.

This definition can be improved, but let's give some examples.

Example 1. Disease, ears and hearing

There is a curious idea in AD&D that you can check monthly to see if the PCs suffer from parasites or mild ear disease. While this feels un-heroic and not particularly exciting, I can see that it would give a campaign a gritty/realistic feels and a sense of urgency (TIME must always have a COST).

[It can also add some gravitas to fights against giant bats, rats and even wolves].

However, the effects of such diseases on usual dungeon activities are not always described. There would be some obvious solutions - for example, diminished chance of listening to doors or greater chance of being surprised - but the book simply does not address this.

If you lose hearing in BOTH ears, the results on "listening to doors" are obvious, even if not described - we'll get to that later. In any case, the results on surprise are not clear.

Similarly, there is no exact consequences to the loss of an eye for ranged attacks, for example.

(Another curious example here is venereal disease. Since the game includes no benefits to intercourse, this just feels disjointed from everything else. Pendragon, for example, has rules for lust and descendants, which might suggest a bigger focus on such issues. Also, the game mentions herbs/gems that ward off disease, but not how they actually affect disease rolls).

Example 2. Time - initiative, segments, weapon speed

My main frustration here is how complicated and disjointed the initiative/segments rules feel.

There is simply a lack of obvious connection between surprise, weapon speed and thief skills. They don't seem to communicate... but they obviously should!

Can a thief surprise a foe with his silent movement? Should a fast weapon be ideal for this job? Can you get more attacks with a fast weapon if your foe is surprised? I'd say "yes" to all of those, but the book either doesn't make it clear or indicates that the answer is negative.

There is also also no clear connection between the speed of melee weapons and ranged weapons, and they seem to work differently in the surprise segments for no apparent reason.

Example 3. Levels, abilities and dungeon/wilderness skills

This is not an AD&D thing, but something common to most versions of TSR D&D. 

As the PCs level up, they get better at fighting and surviving, but they do not seem to improve in any other dungeon activity: listening to doors (or breaking them down), find their way in the wilderness, hunting, etc.

The thief is the main exception here, since most of his skills are dungeon related and get better with level. 

Curiously, the ranger does not have many special skills in the wilderness: he is not better than any other PC when finding his way in the forest. He can cause upraise and avoid being surprise in any environment, but it is unclear how this fits with the vaguely similar abilities of thieves and even halflings.

Example 4. Drowning

I don't remember the source of this; could be some version of Labyrinth Lord. 

But the rule was something like "if you try to cross a river in plate armor, you have 90% chance of drowning".

Just flat 90% (or whatever). Your strength, level or class do not matter. HP? Save versus death? No. You just drown.

Are dead end mechanics even possible?

While I find these mechanics undesirable, I do think there is a natural limit to dead end mechanics.

As I mentioned above, it is obvious that if you lose hearing in BOTH ears you cannot "listen to doors", although the game does not say that, nor does it describe what happens if you lose hearing in ONE ear, which is much more statically probable.

This has something to do with the uniqueness of RPGs.

RPGs give fluff and crunch a peculiar bond, to the point that fluff IS crunch and vice-versa.

This is a long discussion, but in short, in RPGs a spear will NEVER be identical to an axe, even if both deal have the same damage, weight and cost. An axe will ALWAYS be more useful to take down a door even if the game doesn't say so.

My point is: if taking down doors is a frequent activity, the game should address this difference explicitly.

How to write better mechanics

My ideal game would have a big level of integration between the different rules. In the most frequent cases, this should be explicit to make the GM's job easier.

Modern D&D sometimes does a better job at connecting various mechanics. For example, a Constitution saving throw relies on ability AND level AND class. But, sometimes, it creates MORE problems of this kind, like the fact that 5e D&D has at least TWO unrelated ways of disarming opponents (one of them optional), with no clear relation. 

I must mention Quidditch as a negative example (despite not being a big fan of Harry Potter). While there is some nuance, it often feels like two guys are playing an entire different game that has a flimsy relation to the rest of the players and a huge possibility to make all other efforts void.

["A Seeker catching the Snitch ends the game and scores the successful Seeker's team an additional 150 points (15 goals). As the team with the most points wins, this often guarantees victory for the successful Seeker's team." - source].

But maybe I can express this point visually, using the two images in this post.

The spheres represent game mechanics. The biggest ones are the most important/common. They are connected by lines; e.g., Constitution and level should both have direct lines to HP, but Constitution does not necessarily have a direct line to level or saving throws.

The first image in this post represents a disjointed game: no clear center, with some important mechanics disconnected from others.

The second image is closer to my idea: the most important spheres are near the center and strongly connected; disconnected mechanics are few and unimportant.

I think there is more to be said about the subject, but I'll leave it here for now.

As a suggestion, I'll say we must consider what are the central mechanics of a game (maybe abilities,  levels, classes, maybe also time, money, XP, encumbrance, etc.) and how they related to each other. Dead-end mechanics should be rare.

TIME must always have a COST - no 5-minute workdays

I've written a longer post here; this is the short version, more or less.

(I really like that post; I encourage you to read it).

Time must always have a cost.

Resting for one hour in the dungeon is dangerous. But so is resting for one day in the wild.

Resting for a month in a peaceful city should ALSO have a cost.

The cost is usually DANGER. 

It can also be money, until the PCs are too rich to care. Or anything else the PCs might lose.

In any case, there must be a risk that the cost lasts longer than the time spent. 

I.e., if the cost of resting for a day is an encounter that does nothing except take a few HP, they'll just rest another day or two.

If there is no cost, the PCs will ALWAYS fall back to the free/safe state after they have spent some resources, thus creating the "5-minute work day": the PCs enter the dungeon, spend all their spells, and get out of the dungeon to recover them.

Same can be said of HP. It does not matter if the PCs fully recover in one day, one week, or one month if there is no cost to that.

Even after a month, it is unlikely that the monsters will "re-spawn" (although I love to add certain undead that rise again every night until the source of the curse is destroyed).

But maybe they should just leave (with all the treasure) or call for reinforcements. 

Otherwise, the PCs can always "reset" their losses with no costs for the opposition.

It is like they are playing chess, and they can always reset their clock arbitrarily - and even replenish lost pieces - but their foes can't.

Until, of course, they suffer a check-mate (or TPK). 

This is hard to happen if the PCs can just choose to leave at any time, but it can still happen against opposition that is much stronger.

I'm tempted to say the game ends whenever the PCs reach safety (or, again, in a TPK). You can start the game again with the same PCs after a day of after after a season, but then it will be a different game. If they go back to the dungeon, the dungeon will have changed.

Having a game without any risk feels a bit boring.  The only way to have a meaningful campaign that never really "stops" is to keep that in mind.

Note: the New Year, New Game sale is on. I'm thinking of getting Crypts and Things Remastered - let me know if you have read it! But there are tons of other games on sale.

(affiliate links)

Nothing to lose but their lives (stakes)

D&D characters usually have nothing to lose but their lives.

They lose HP, yes, but if they don't die, they can usually recover most of it in a day (in old-school D&D requires a cleric for that, but they are still good to go in a day or two).

And HP loss doesn't mean anything except death. You do not get slower, weaker or poorer because you lost HP. As long as you don't die, you're good to go.

So either they lose NOTHING, or they lose EVERYTHING.

The stakes are ALWAYS at a maximum, with no room for maneuvering.

In most games, taking a hit means you have to DEAL WITH YOUR LOSSES, something D&D PCs rarely do.

Think of a game of chess; when you lose a piece, even a pawn, you're hindered for the rest of the game. What about a soccer match? A goal leaves you behind, but you can  recover from that and even turn the tide in your favor. 

Fighting is even more interesting: you win/lose rounds while also managing stamina, wounds, etc., AND you always have the chance of a sudden reversal of fortune, no matter how many rounds you already won or lost.

The system (kinda) works in DUNGEONS, since you have limited resources, limited time, and to restart you'd have to leave the dungeon. 

But it doesn't seem to work in wilderness play, where there is only one encounter or two per day. Even if you're playing only dungeons, they become a bit boring if the only two results from delving deeper is a binary "get richer or die".

This has been a problem for me in practice.

How to fix it? 

Let's consider some alternatives.

TIME - Unless there is some kind of ticking clock, players do not give enough importance to time. As noticed above, they can only lose a day or two. Maybe if we slow down everything - recovering spells, wounds, etc. - we'd have more meaningful consequences. E.g., "you can recover all your resources after a few weeks, but now it is winter...". I've noticed that even without a ticking clocks some players automatically give a week's rest more gravitas than a day's rest. Adding random events can also help things immensely.

LEVELS - A few monsters do this, but it has been widely criticized and largely abandoned. It could work for some monsters, but what would we do with the rest?

HIRELINGS - Not only can they hire more, but they can even save their salary if they perish. You'd need to make PCs care about NPCs, or at least limit the number of hirelings, force the PCs to provide some kind of insurance, etc.

NPCs - Maybe the PCs already care about other NPCs (family, allies, etc.). But it is unlikely that they travel with the PCs, and feels unfair to just kill them off-screen - unless there is a previously known ticking-clock attached to the event.

LIMBS/WOUNDS - Lasting wounds could make a difference. Healing them might require weeks or a quest. In some cases, the PC would just have to deal with an impairment forever.

GOLD - In my experience, PCs get rich soon, and accounting is just not that fun. I don't want to deal with taxes and fines in my games. That is boring enough in real life. At most, I might require a monthly upkeep for food and housing, but this unlikely to make a dent in the PC's finances. Maybe the PCs will buy/build castles, but they have to decide that for themselves - and if I burn those castles, they are unlikely to ever build new ones.

ITEMS - Monsters that destroy weapons, spoil magic items, etc., feel a bit forced, but could work. Even better, we could have magic items of limited uses more often, which would force some strategic thinking.

REPUTATION - I think this would be a good solution, but it requires some deep reflection/preparation on the wider world - or use some reputation MECHANIC (i.e., IIRC there are some in Pendragon, Oriental Adventures, etc.)

SANITY/STRESS/ETC. - You could have different mechanics to represent other kinds of losses. Call of Cthulhu has sanity - this is hard to recover. Darkest Dungeon has stress. Adding other gauges in addition to HP grants the game some tactical depth. Exhaustion from 5e is an interesting one, since it bypasses HP and has other consequences (affects speed, skills, etc.).

Come to think of it, exhaustion and stress could be a great solution to this "you get better in a day" problem. But that also deserve a post of its own.

DEATH - In some versions of D&D, death is nothing but a "lasting wound". If raise dead is widely available, death might represent a new goal or quest to save the dead PC (maybe with a ticking clock), a cost in gold, a few weeks of downtime (e.g., in B/X it takes at least two weeks to recover). 

[Come to think of it, just considering 0 HP to be "grievous wounds" and replacing raise death for some kind of "cure grievous wounds spell", with a small chance of failure, could make the game significantly grittier and less magical without significantly altering the rules].

NOTHING - What if death is really off the table and the PCs really have nothing to lose? This seems to be a common trend in modern games. I can't quite see the point in a game with no real stakes. Of course, PC death is an issue to be dealt with - you can have raise dead (maybe at a cost), automatic resurrections a la Dark Souls (which also has a cost), on mere unconsciousness. 

If even death is inconsequential, you probably need to find consequences elsewhere.

A proposal

I think I'd like my games to have multiple lasting stakes at the same time. Instead of just dead/alive or even zero to full HP, I want consequences to affect characters thought time. 

As I've often insisted, spell shouldn't just renew everyday. Maybe some spells can only be performed once a year, or once in a lifetime, requiring the blood of a nearly-extinct beat.

A character could lose an eye, gain a few levels, so that he is a better fighter but a worse archer, and in any case much more powerful because of his new allies, while still threatened by stronger enemies.

This is the kind of games RPGs are supposed to be, IMO. Every decision can be relevant for ages to come. 

There is victory and defeat, but trade-offs are much more common.

A conclusion (?)

RPGs are games. Game should have stakes, unless there is a reason to do otherwise. At the very least, be mindful and honest about these.

When creating adventures, running games, describing scenes, etc., consider the stakes.

In addition, let your players know the stakes.

Sometimes, they PCs will be surprised by a monster or trap they couldn't have anticipated. This should be RARE, and even then there will always be SOME choice involved - sure, they got surprised, lost initiative and were slain by a dragon before they could draw their swords, but they did wander into the haunted forest after all!

Most importantly, let them know what kind of game they are playing, from the beginning.

If you will fudge the die and the PCs can't die, let your players know beforehand (or right after it happens). If they need to be captured because you "planned" the next "scene", let them know. And if you want to ban, or introduce, fudging, maiming and death to your stories, talk to the players before you do.

Playing a game without knowing the stakes is just unfair for all involved.

Single attack/damage roll (kubular), but divided in half

I think I discussed that idea at the time, but I didn't write down this exact implementation. Read that post before this one! This method has several advantages over the usual D&D method.

Here is the deal: no more damage rolls.

Just roll 1d20 plus modifiers and subtract AC, then divide by two: this is the total damage (minimum 1).

Modifiers include attack bonus and weapon rating (WR).

WR usually goes from -3 (unarmed) to +3 (heavy 2H-weapon).

A dagger has +0 WR; other weapon are easy to figure out (d6, d8 and d10 become +1, +2, +3).

Improvised weapons, gauntlets, etc, have a WR of -1 or -2.

Lets assume ascending unarmored AC 11 (like BFRPG).

A dagger hit deals an average of 3 damage against unarmored targets, a bit over the original (nice!).

A 2H-sword, OTOH, deals 3.77 damage on a hit, but hits more often than in the original BFRPG; the DPR (damage per round) is about 2.45, a bit HIGHER than the usual 2.25.

What about heavy armor? Say, Plate mail is AC 17 in BFRPG. 

To hurt someone in plate with bare hands, you need a natural 20 (realistically, you'd be more likely to hurt your hand... add some grappling rules to your game!).

A dagger will only deal 1.5 points of damage. 

A 2H sword deals an average of 2.5 damage (originally 4.5), but again the DPR is 0.8, not far form the original (0.9).

I'd definitely combine it with some "armor defeating" rules for maximum effect. E.g., cutting weapons deal 1 point of additional damage if they hit, maces get +2 to-hit against chain or heavier, axes are +1 against everybody, etc.

Time scales: rounds, days, weeks, expeditions

"For want of a nail the kingdom was lost"

Time keeping is extremely important in D&D. 

Everyone knows that since Gary Gygax said in the AD&D 1e DMG, in all caps, that YOU CAN NOT HAVE A MEANINGFUL CAMPAIGN IF STRICT TIME RECORDS ARE NOT KEPT.

But I think few RPGs - and maybe not even AD&D - has got this exactly right.

One concern I've shared here before is how spellcasters recover all of their spells OVERNIGHT. This becomes a problem because fighter can take up to four weeks to recover lost HP. And, while spells must be chosen every day, equipment is usually chosen once per expedition.

These things are operating in different time scales.

- Losing some HP may "cost" you a month (resurrection also costs you a few weeks).

- Losing all your rations might ruin your entire expedition*.

- Losing spell slots costs you a day at most.

(*An "expedition" is the travel from a safe city to a nearby dungeon or other challenge. In other genres, we could have a "job", "mission", "heist", etc).

If you have spells that produce HP or rations, the rhythm of the HP and ration recovery is broken. Which is not a problem "per se", if you are conscious of the effects.

For example, if a PC takes weeks to recover HP, this could encourage players to "rotate" between multiple characters. A cleric with "cure light wounds" can basically avoid this process, except when there is need for resurrection.

There is a certain rhythm to D&D - each RPG has its own.

In Pendragon, there are "time skips" that take years, and rule for how you can play with your heirs. Likewise (IIRC), wounds can take a lot of time to heal.

In DCC RPG, there are lasting consequences for magic - you can get mutations, spell mishaps, etc. Some of these are permanent (IIRC). This is not a problem, but I think other classes should also be subject to permanent consequences - say, scars and losing limbs (which is a thing in DCC, IIRC, but not usually in D&D).

Runequest suggests "one adventure per season" and - AFAICT - this interacts with income and experience rules.

In 4e D&D, there are daily, encounter and "at will" powers for ALL classes, so everybody in playing in the same tempo. It might have been too radical, making classes feel a bit "samey".

In 5e D&D, there are few consequences that can last more than a day. All spell slots are recovered, yes, but so are all HP and other powers. Even "raise dead" only takes four days to recover. There are also "short rests" that allow you to recover some HP, slots, etc. during the day.

The tricky part in 5e is keeping the short rest:long rest ratio. 

You see, some classes are better with long rests, others with short rests. If you mess up the ratio, 5e's supposed "balance" goes out the window. That is why 5e attracts bizarre concepts such as "seven encounters per day", which sounds good in a dungeon but silly in the wilderness, city, etc.

Old school D&D has a similar problem (well, like all RPGs).

First, there is this wilderness/dungeon divide. B/X recommends at one encounter check per day in the wilderness. But even if you're making three or four (which is optional), it is unlikely that will lead to more than a couple of actual combats if you're using the reaction table and evasion rules. 

But in the dungeon you check for encounters every TWENTY MINUTES. This changes the game completely. Now spell slots are precious few - at least for the first few levels.

However, PCs are not supposed to go to the wilderness until level 4. By level 5, a MU might have a 5d6 fireball that can destroy many wilderness encounters. 

On the other hand, if you "nerf" the MU too much, he is helpless in the dungeon after casting a couple of spells.

I think this is why a first level MU feels too weak and a 10th-level one feels too strong. Nerfing the MU requires giving him cantrips or at least a sword to compensate.

AD&D has aging rules. Unless you get cursed by a spell, these do not really matter, because no game mechanic interacts meaningfully with "years" (unless, maybe, building a castle or similar). Similarly, weapons have different speeds, which can interact with spell interruption and so on.

Then we have rounds, turns, hours, days, etc. Torches burn for an hour, which is 6 turns, or 360 rounds. Running out of torches might force you to spend days to go back to town, or, worse, can leave you lost in the dark.

I'm not suggesting a simple fix; instead, I'm encouraging you to reflect about which time scale your games are about, and how scales interact.

And, of course, keep strict time records and let your players know about it. 

The "5 minute workday" problem happens because there is no cost to wasting a day. If there is also no cost to wasting a few weeks, the PCs will start every encounter fully rested and healed regardless of healing spells and potions. And so on.

I have to reflect on how to implement this myself. In my current campaign, the PCs decided to leave a mission against certain goblin tribes that were harassing a nearby village. 

What happens when then go back? 

The answer should certainly be affected by how long they take to go back. If I just hand-wave time, we go back to "time railroading" and decisions about time become meaningless.

I've said before that "Time seems to be the glue that holds many rules together: Healing, researching, building, random encounters, searching, torches, diseases, etc. 

Once you ignore it, everything seems to come crashing down. Maybe this is one of the fundamental ideas of old school play."

Come to think of it, this is much bigger than "old school play" - or even RPGs. 

The interaction between different time scales is an existential question.

If I eat a chocolate now, I will feel good for seconds, and it might take weeks of chocolate to get fat, and months to lose that fat.

To write a book, I have to put an effort for hours and days, and then I'll have it forever (or until the next revision).

A kind word to a loved one might make little difference now, but every moment can eventually add up to me looking differently to the past twenty years.

And ultimately, maybe we have to consider time scales that include more than a lifetime. Maybe PC death is necessary for PC lives to be meaningful; if everything (i.e., the campaign) ends because of a TPK, what difference did the PCs make?

But that is probably a subject for another post.

(Yet another) critical hit system for B/X, AD&D etc.

 It is quite simple:

A) Natural 20 means maximum damage.

B) Beat AC by 10 or more means double damage.

This has several advantages.

"A" gives you a quick, optimal result that is still within the expected boundaries. You can deal maximum damage at any time, but a natural 20 guarantees it. No "whiff factor". The average damage is not significantly impacted.

And "B" gives you:

- The fighter to get a small boost in damage, especially against weak foes, which is good.

- Armor becomes more important - going unarmored is now a terrible idea.

- The thief gains more damage with backstabbing. This is good for B/X but maybe unnecessary for AD&D. OTOH the B/X thief becomes a bit more frail due to light armor and low HP.

Both give more importance to strength bonuses and magic weapons, and even make two-handed 1d10 weapons a bit stronger (although a shield also becomes more important).

But what if both happen at the same time?

There are several solutions.

- Double maximum damage. This would occasionally allow a B/X fighter that usually deals 1d8+2 damage to deal 20 damage with a single blow.

- Double damage, but ONE of the dice is automatically maximum damage (i.e., 1d8+3 becomes 8+1d8+6). I like this solution because the maximum damage is still impressive, but the average is a bit lower.

- Double damage plus another attack. I like this one because it gives the fighter some cleaving.

A caveat: monsters will get more dangerous too.

This is not a HUGE problem IMO; I like dangerous monsters, and with multiple attacks monsters are likely to spread the damage a bit. But it is something to keep in mind.

Some MMA-Melee reflections

I was talking about "medieval MMA" on twitter the other day and another user (@D20Gary) made a good point about how every attack "hits", and we could just roll damage instead of "to-hit" like Cairn does.

Gary makes a good point - in melee, almost every attack "hits" - even if only "hits" shield, armor or weapon. 

It is very rare that someone would hit air.

However, I disagree with the solution (and don't use a Cairn-like system), because not every attack DAMAGES.

Look at the video below, for example. Several attacks "hit" armor but not necessarily HURT.

It is often said that a "miss" in D&D could be a glancing/weak hit.

Although practice might vary from table to table, it is obvious that it must be so - just think about the numbers and what AC means.

E.g.: say your fighter "hits" by rolling 8 or more against an unarmored foe.

If the foe is using plate, a 8 or more obviously mean you still "hit" the target, but with not enough skill to bypass/defeat armor.

This can be seen in the video, over and over.

Another problem is that each fight like the video takes dozens of "hits" or more to  finish. 

Even with an average of 1d6 damage per round, every fighter would need 60+ HP, leading to HP bloat.

(This could be avoided by adjusting damage - apparently, Cairn does this by subtracting armor from damage, which is good).

So, even in the context of the MMA-melee video, a D&D-like system seems to make more sense - decent level fighters constantly "hit" but not always "damage".

HOWEVER...

I agree that needing TWO rolls for attack AND damage is redundant, ESPECIALLY if you consider "misses" are not necessarily MISSING the target.

The hit/miss binary is just too "low resolution" - doesn't measure quality or even separate "misses" from actual misses (i.e., "hitting air").

My favorite solution would involved a single d20 roll with some nuance. This has been attempted in several ways in here (see links below), and by many before me.

Anyway.

On a related topic.

What we said above is true for "MMA melee", but not so for actual MMA or boxing - it is not unusualk to "hit air". Same for shooting bows, etc.

Now think of the various forms of combat:

- Unarmed, which includes striking AND grappling.

- Melee with armor. 

- Melee without armor (e.g., fencing). 

- Bows. 

- Firearms.  

These are so incredibly DIFFERENT in reality that a single system is unlikely to work well for ALL types.

A dagger fight ends in minutes without armor, but can last HOURS in plate.

Add a knife to a boxing (or wrestling) fight and it changes EVERYTHING.

Just change the surroundings - from forests to tight dungeons - and the whole dynamic is different.

Lethality, speed, distance, % of hits landed, lasting wounds, etc. are just too diverse.

So, you either have SEVERAL combat systems or accept that these things will be mostly abstract.

It is difficult (maybe impossible) to have a system that is both realistic AND simple - not to mention FUN to use at the table.

Still, we keep trying...

Additional reading:

https://methodsetmadness.blogspot.com/2024/01/single-attackdamage-roll.html

https://methodsetmadness.blogspot.com/2024/02/hitting-armor-in-d-glancing-blows.html

https://methodsetmadness.blogspot.com/2023/06/minimum-combat-detail-deadly-daggers.html

https://bxblackrazor.blogspot.com/2024/07/d-combat.html

Unlimited D&D x Limited D&D

These are two different perspectives for playing D&D, or, more specifically, running/DMing D&D. 

One is that your options are somewhat limited whatever is included in the game rules (I'll call this "Limited D&D" or LD&D). 

The other is that there is no such limit, and the DM can come up with whatever he deems necessary for his campaign ("Unlimited D&D" or UD&D).

This is not about "House Rules x RAW", however. 

It is about the number of pieces you get to build your setting: for example, how many monsters, races, classes, magic items or spells you can use in your creations.

I would guess most groups would quickly accept that the DM can include new monsters to the setting as desired, but this is an assumption that often gets ignored when discussing old school D&D. 

For example, I always found that "immunity to ghoul paralysis" was a silly trait to give a class or creature because it is so specific. But if you are only using Moldvay's Basic - and not even expert - it could be an interesting advantage, since the total number of monsters is low. Still, people keep using it even when playing some form of UD&D.

Same for the cleric "turn undead" tables that include the NAMES of the creatures turned instead of their HD. If the number of undead are limited, this makes perfect sense; otherwise, it looks strange and impractical.

(A more extreme example is the blink dog and its hatred of displacer beasts. B/X tell us almost nothing about these creatures, but they attack each other on sight. How often will that happen? If you're playing UD&D, almost never).

There are other aspects of old school D&D that seem to be remnants of this limited mindset. For example, clerics and mages cannot use sword, which is important if most magic weapons are swords, but becomes less important if you have several magic maces or daggers.

Another example I've been struggling with lately is spells. I've been running a game slightly based on B/X, which does not contain "counter spell", exactly. But now I'm introducing an NPC for another system that has this spell. Is it fair to my caster that he didn't get to choose it?

(My solution for this is: if my player shows interest in Dispel Magic, I'll let it function as a counterspell. Fortunately, he hasn't got it so far).

Personally, I was always attracted to this "Unlimited" take on RPGs in general. I'm willing to add new monsters, spells and even the ocasional laser guns to my games, and always tried to accommodate every character concept the players suggest (although now I'm tempted to go mall-human for the next campaign).

But there are advantages of the "limited" perspective - it allows players to get more familiar with existing monsters, spells, etc., for example.

And, in general, I want to expand the boundaries rather than destroying them. I would definitely not limit the number of monsters I can use in my games, but I'm perfectly satisfied with running a limited number of monster types: undead, giants, humanoids, beasts, etc.

In fact, having fewer monster types reinforces their significance rather than diluting it.

(This is partly what Teratogenicon is about, BTW).

If every single monster, spell or item the PCs find is completely new, they can never learn anything except trough direct contact. There is no room for extrapolation, generalization, etc.

I have a similar feeling on classes. Yes, I like paladins, assassins, warlords, druids, avengers, and monks. But rather than having a dozen classes, I prefer having FOUR: fighter, mage, thief, cleric, each with a few variations. And I think the AD&D bard - a class that works in a completely different way from other classes - is an unnecessary mess.

(Maybe I'll reduce it to THREE classes for my Sword and Sorcery game, ditching the cleric).
Even 5e seems to have problems with this (correct me if I'm wrong; I don't play 5e anymore). For example, the "Staff of Charming" requires attunement by "a bard, cleric, druid, sorcerer, warlock, or wizard". But what if I'm using a 3rd-party class, or even the very popular artificer? Are they automatically excluded? Or do including a class requires rewriting all magic items like that?

As you can see, seeing classes through a limited scope simplifies some aspects of the game.

(This is partly what Old School Feats is about, BTW - no extra classes but many additional options. You can look at the free previews to see how I treat fighters, for example: a framework to create warriors, paladins, rangers and warlords).

In short, my favorite approached to D&D is having unlimited choices within a limited framework that works as a common language between players and DM.

Inverted Target 20 - Trained/Untrained

If you have been reading this blog for a while, you know I'm a big fan of Target 20.

However, in the last few days, I've been thinking of an alternative that is even simpler. I'm not the first one to have this idea - I've seem something similar in at least two or three OSR games.

Mathematically, it it's very close to Target 20, but it uses a method that resembles THAC0 and saving throws. Here it goes.

You have two numbers in your sheet, in addition to ability scores* and modifiers: Trained and Untrained.

(* I've been considering 4d4+2 or a 9, 10, 11, 12, 13, 14 array).

To succeed, you need to roll 1d20+mod, equal or over this number.

Notice that the chances of succeeding when you are untrained are about half when compared to a trained PC (e.g., by level 5, the chances are 30% and 15%).

And this replaces:

- Saving throws. I'd say every adventurer is trained in saving throws. Some classes or situations deserve a bonus.
- Skills. Thieves are trained in their usual skills. But you could add "training" to rangers, for example, to forage or find tracks.
- THAC0. Works perfectly with descending AC. Only fighters are trained in combat.
- Ability checks. If you are untrained, this is how you can attempt to do thief (or ranger,etc.) stuff.

- Spellcasting, if you want roll-to-cast.

This has some advantages over Target 20:

- Level is calculated in advance, you only roll 1d20+ability mod.
- Comparing values is even easier than addition.

I'm somewhat tempted to leave this table in the hands of the DM - the PCs just roll 1d20+mod, period, telling the DM if they are trained or not.

But, overall, Target 20 feels somewhat easier to grasp for my players - they expect bonuses over a descending number.

I am a bit doubtful about what version to use in my next game.

Anyway, if you like how THAC0 and Saving throws work in old school D&D, however, this might be  a good alternative!

Notice that the two systems can be used interchangeably, as the "trained" values are mathematically identical to suing Target 20.

How many leaders? Demographics of command

Just a small thing I noticed examining B/X encounters.

Some humanoid groups have a 2 HD leader for every 10-20 people, a 4 HD leader for every 40, etc. 

A few examples: merchants, pirates, brigands, etc.

It changes from creature to creature, but it would be easy to say, for example:

- One 2 HD leader for every 20.

- One 3 HD leader for every 30.

- One 4 HD leader for every 40, etc. 

Maybe up to level 9 (or lower for demi-humans; humans are the most organized and can get more levels).

If you ever find a group of 100 warriors, it would be organized like this:

- Led by a 9th-level warlord.

- One of each level 6, 7, 8 characters as advisors, maybe clerics, magic-users, etc.

- A couple of 5th-level captains.

- A couple of 4th-level lieutenants.

- Three 3rd-level and five 2nd level lieutenants.

This assumes an organized army. About 20% of the individuals are above 1 HD.

But most groups are way smaller, and it only have 10% of exceptional individuals or fewer.

I used to think the best way to calculate the number of exceptional people in a population was exponential: for example, one out of ten fighters would be level 2 or more, one out of a hundred for level 3, etc.

You'd need a army of MILLIONS to find a 9th-level fighter!

But come to think of it the difference between level 5 and 6 is not as extreme as level 1 to 2, so maybe level 6 is just a bit less common than level 5, a suggested above.

For larger populations (cities etc.) I'd say 50% are simply non-combatants, 25% are level 0, and 25% level 1 or more.

Anyway, it is nice to have more leaders. Gives NPC bands more personality.

This should definitely affect morale, BTW. 

I always found odd that you can defeat a group of 40 by killing one and forcing a morale check. 

Maybe this applies to leaderless groups - but with a leader, you only check when the leader or half heir numbers is killed, for example.

Anyway, just something to consider for my future encounters.