Weapon vs. Armour in Chainmail vs. AD&D

Disclaimer: Note that some of the links below are affiliate links (meaning I get a small percentage of the sale without extra cost to you or the publisher).

Also, I'd like to give a big shout out to waysoftheearth over at the odd74 forum for his insights. My original goal was simply to reproduce his calculations and to be able to compare variations myself — like I do so below.

I have recently talked about some aspects of the man-to-man combat tables in Chainmail (and even shared my calculations so that you can play around with your own variants). It occurred to me that there's a weapon vs. armour table in the AD&D Players Handbook as well (which has been shown to be wildly different from that in Chainmail) — wouldn't it be fun to compare the two?

Here is the weapon vs. AC table in AD&D. As a reminder, these are modifiers added to the to-hit roll with a d20. Armour Class (leaving Dexterity aside) is determined as follows:

For a level 1 fighting-man, the minimum required to hit these AC values is (20 minus AC). so 10+ on d20 hits an unarmoured foe, and 18+ hits someone in plate and shield.

To compare these values to those in Chainmail, we need to cut some of it. The Chainmail tables only include thirteen different weapons, and the armour categories are also different (for instance, chain, banded, studded, and splint mail all belong to the same category). To make things easier, we will only consider the following armour categories: no armour (AC 10), shield only (AC 9), leather (AC 8), leather & shield (AC 7), chain (AC 5), chain& shield (AC 4), plate (AC 3), and plate & shield (AC 2) — leaving out AC 6 for now.

Most weapons in Chainmail have a clear equivalent in AD&D, but note the following:

• for mace and flail we'll use the footman's mace and flail
• sword is interpreted as longsword
• polearms, a single entry in the Chainmail table, are left out because AD&D has different stats for each variant
• lance is similarly left out for now to make things simpler

Edit: I made a crucial mistake in my calculations, essentially flipping the modifiers in AD&D. I'd like to thank everyone who pointed this out! My conclusions are also rewritten to reflect this. Apologies for the errors in the first place.

If we calculate the minimum requires rolls for a level 1 fighting-man with these weapons vs. the discussed armour categories, we get the following:

 

 

And here are the percentile chances of hitting compared to Chainmail:

 

In AD&D the average difference in performance is minimalised; blunt weapons are generally much worse against heavy armour than in Chainmail (cf. mace 20% vs 41.67% or 25% vs 58.33%); and the two-handed sword doesn't vastly outperform all other weapons.

Now, what if we make a direct conversion from Chainmail instead? If we take the percentile values and convert them to target numbers on the d20 scale, we get the following:

Of course, lance and polearms are still too ambiguous in AD&D terms, but it's definitely a starting point. Now, for the last bit, here are the to-hit modifiers for the above, presented in the AD&D format (AC 6 left blank and up for interpretation):

Editable Chainmail M2M Tables

This is going to be a short one.

In my last post I shared some statistics about the man-to-man tables in Chainmail. Here's a link to my calculations, with separate sheets for the numbers as presented in the book and another to play around with (Raw and Mod, respectively). To edit your own version, go to "File" then "Make a copy". Have fun!

On Chainmail's Man-to-Man Tables

On and off I've been working on Láncvért, a supplement for Kazamaták és Kompániák that integrates most subsystems found in Chainmail into the KéK framework in a much less confusing way than the original (at least that's my hope).

One of the many interesting bits in Chainmail is the man-to-man combat system (the one that was supposed to be used with OD&D according to the rulebook, although apparently even the designers disagreed). It's a fairly simple 2d6 table where you check the attacker's weapon and the defender's armour to see your target number; if you meet or exceed your target, the defender is killed (or dealt one die of damage in D&D terms).

Below you can check the table (colour-coded for our convenience); I also added averages (and rounded averages) for each weapon and armour category as well:

The bell curve can be a little counter-intuitive, so I also included a handy chart with percentages. Don't be confused by the colours; I decided to swap them so that red means "hard to kill" instead of "meagre defence" here:

We can already see some interesting things here. For some reason, the spear seems to be the worst weapon in terms of stopping power. Two-handed swords vastly outperform all other weapons (including the mounted lance!), followed by the flail and the morning star.

Leather armour is virtually the same as no armour (it only makes a difference against a dagger or a sword). Shields, however, are really good. In fact, if you have to choose between picking up mail armour or a shield, you should go with the latter.

I also made some more detailed comparisons between various armour types:

Curiously, mail armour makes you more susceptible to being killed against a number of weapons (possibly because the manoeuvrability you sacrifice is greater than the protection of the extra armour that the weapons in particular can bash through — at least that's my theory).

Shields, if we look at them closely, always improve protection, except in one case: against a halberd and paired with leather armour.

There are more rules that go into this subsystem, of course, but this is the main engine. I quite like the extra differentiation between weapons, but I'm not convinced about the specifics. Further testing needs to be conducted until I find a happy middle ground.

The Underappreciated Combat Table of Barbarian Prince

Barbarian Prince is a great little game from 1981. James Maliszewski over at Grognardia posted a short retrospective in 2011, and in 2020 Anne from DIY and Dragons wrote an excellent three-part analysis (Map and Layout; Main Menu; Characters, Followers, Encounters, and Combat). It has been recently on my mind partly because of the Drifter series (see my review of the first game here) and a four-part actual play series by the Lone Adventurer.

Today I only want to look at one specific aspect of Barbarian Prince: the combat result table.

The gist of it is this: roll 2d6, add your Combat score, subtract the enemy's Combat score, apply modifiers if any, and consult the chart below to see how many wounds the attack inflicts.

taken directly from Anne's part 3 post linked above

Anne points out how the wording in the original rules is confusing and how the table above makes no logical sense. The Lone Adventurer criticises the rule for a similar reason. I didn't go looking, but I imagine other people being baffled by the above table.

However, this table is actually pretty ingenious. Let me show you a table of the average expected damage results arranged by final modifier to the 2d6 roll.

The first column shows the final result; next to it you can see how many wounds that roll inflicts upon an enemy. The columns after that alternate between showing the percentage chance of a result (given the final modifier noted on the first line) and the expected damage. The bottom two lines show the average expected damage per attack based on the final dice modifier as well as the percentage chance of inflicting at least 1 wound (i.e. the chance of hitting).

As you can see, the average chance to hit steadily increases (up until it plateaus at 83.34%, while also retaining the increase in average damage). The way the table is set up allows the chance to hit
(basically) to follow a gradual progression whereas if it was a standard 2d6 roll (something like 2d6+mods vs a target number), the progression would be much steeper.

Of course, whether the added granularity and hard-capped accuracy is worth having a chart is something we may disagree with; I can at least point out how deliberate the numbers are, and the fact that such granularity can be achieved on a 2d6 roll is just interesting to me in and of itself.

AS&SH Average Damage per 2 Rounds

I have made another spreadsheet that I thought might interest others as well. This time I was calculating the average damage output of various weapons in AS&SH.

Here's a breakdown of what's in the spreadsheet:

• Average damage output was calculated for all FA/HD levels vs. all non-negative AC values.
• The numbers show average damage in 2 combat rounds (!) because the number of attacks often alternates.
• Each sheet contains details for a single type of weapon (such as bows, light/heavy crossbows, 1d8 melee weapons, etc.).
• "Dmg" is for the weapon's average damage, "To-hit" and "DmgB" cover bonuses from high attributes and weapon mastery, while "#Atk" and "#Atk7" show how many attacks are made in two rounds level 1-6 and 7-12, respectively.
• Melee weapon damages are calculated with fighter types in mind (other characters have the same attack rate throughout all levels).
• Four primary circumstances are covered: (1) no mastery, average attributes, (2) no mastery, high attributes, (3) mastery, average attributes, and (4) mastery, high attributes. Details are added in notes.
• The last four sheets cover the following special cases: (1) bow vs. damage reduction 1, (2) light crossbow vs. damage reduction 1, (3) bow vs. damage reduction 2, and (4) heavy crossbow vs. damage reduction 2.

Here are my findings:

• Weapon mastery is even stronger than I suspected. Without weapon mastery, it takes 2 rounds on average for a 1st level fighter to kill a zombie (HD 2, AC 8). With weapon mastery, it takes only 1 round.
• A fighter with a two-handed sword (3d4 dmg) has a lower average damage than a fighter with a longsword (1d8) having mastery (until level 6 at least). Note that these numbers don't take damage reduction into account (but also note that monsters don't usually have damage reduction).
• Crossbows are supposed to be better against armoured opponents, but the fact is they are outperformed by bows (provided the archer is stationary). Light crossbows outperform bows against medium armour only if the archer moves before shooting (thus having a reduced rate of fire). Heavy crossbows are even worse against heavy armour: they only outperform (moving) archers from level 7 and on.

Static Damage Reduction vs. OSR Damage Rolls

Under a Reddit post concerning damage reduction in OSR systems a commenter proposed the idea that maximum damage rolls could bypass armour, ensuring that even low damage weapons (such as daggers) wouldn't be rendered completely inefficient against armoured foes. The nerd I am, I made a spreadsheet to calculate the modified average damage outputs (a perfect pastime for a lazy holiday): column A shows the die size, columns B-M the reduced damage output corresponding to the roll, and column N the average. The first sheet assumes armour may completely negata a hit (cf. zero damage), while on the second a single point of damage always goes through. These rules are summarised in column P on both sheets.

Current AS&SH House Rules

Attribute Generation
Roll 3d6 in order to generate your first array. Your second array is the inverse of this (18 and 3, 17 and 4, 16 and 5, etc.). Choose whichever array you want. Make sure you qualify for the class you want to play.

This house rule is taken from Esoteric Enterprises (aff link), and it's supposed to provide a nice middle ground between 3d6 in order, 4d6 drop lowest, and 3d6 arrange to taste. I personally haven't tested it; I just assume Cavegirl did.

Hit Points per Level
Upon attaining a new level, either roll a single HD (plus CON modifier) and add the resulting amount to your total HP, or reroll all your HD (and CON modifier times your new level) to determine your new HP total. If the reroll would result in no increase in HP, increase your total HP by 1 instead.

This is a house rule I have been using for years now. It has worked fine so far. The intent is to alleviate the impact of really bad hit point rolls in the long run.

Scroll Use
Spellcasters can identify scrolls of any tradition. They can also use scrolls of any spell level. When they use a scroll of a different tradition, there is a 2-in-6 chance of miscasting (1 random target, 2 half efficacy, 3 half duration, 4 lose 1d4 random ability points, 5 opposite effect, 6 different spell of same level).

This one's a bit trickier. I haven't actually tested it at all. Since AS&SH uses so many different spell schools, the scrolls in most OSR modules would need to be tweaked, otherwise only Magicians and Clerics would have a chance to find usable scrolls (let alone learn new spells). This house rule is basically my lazy way of handling that instead of rerolling every scroll found on the fly using the tables in the rulebook, while also helping out casters in situations where I actually do roll on those tables.

Encumbrance
Encumbrance limits are calculated based on one’s Constitution score.

This one we haven't tested yet, although The Nighmares Underneath (aff link) already does this. It makes more sense in the fiction (because encumbrance isn't really about raw strength but endurance, plus STR already has so much going on for it.

Critical Hits
If an attack roll is a natural 20, use the standard critical hit table in the rulebook. Furthermore, critical hits add a notch on the target’s armour (or shield, if they so choose).

Critical Misses
If an attack roll is a natural 1, the attacker chooses among the following options:
1) Weapon gets a notch (-1 to-hit and damage per notch; breaks at 3 notches)
2) Attacker is disarmed (weapons falls 2d6 feet away in a random direction)
3) Attacker gets off-balance (-2 AC penalty for 1 round)
Unarmed attacks always result in off-balance, while ranged attacks always result in a notch.

Weapon notches have been part of my game for a really long time (about 30 sessions, probably more), and they have proven to be a very nice addition. The intention is threefold: (1) to incentivise bringing more weapons along, while balancing encumbrance; (2) to surprise the GM and the players at the table at times; (3) and to provide another resource to juggle, one which is decoupled from levelling. Repairing weapons costs one-third of its gold value per notch, which is especially expensive for magical weapons (although they are able to withstand more notches in general). High quality weapons are easy to model in mechanical terms without introduction to-hit and damage bonuses, too. It also generates anecdotes, like the fight with a bunch of skeletons, where the party suffered like 10 notches and had to retreat immediately, even though they had plenty of HP and spells. Even trivial fights may deplete precious resources now, which is a huge positive for me. As for the other options, I have tried similar outcomes in the past, but this is the first iteration I find actually fitting. This way every attack has a possible negative outcome, but there is also player choice involved for most cases.

Grim Tales Combat Redux

I have been slowly working on Grim Tales (a dark fairy D&D-esque game with an implied setting; sort of my contribution to the thematic games list) behind the scenes, but it was actually Brendan's latest post that inspired me to finally work out my Reactions.

Characters are basically either proactive on their turn or reactive in others' turn, but being reactive is just that: you forgo being proactive. I still need to work out the numbers, though, but playtesting will surely help with that.

Snippets from Grim Tales Combat Rules

In dramatic situations, such as combat, the sequence of events becomes increasingly important, so determining who may act after whom is necessary. Participants (PCs and NPCs alike) roll 1d20 + Wits (+other bonuses if any) to determine their initiative score, based upon which they are placed in the Combat Queue in decreasing order. Equal scores favour PCs, and further ties are broken by negotiation between the players.

The first character in the Queue takes two actions (either two Minor actions, or a combination of a Major and a Minor action), then they are placed to the bottom of the Queue, and the next person takes their turn, and so forth. Characters may have a Reaction even when it is not their turn to act. That, however, puts them on the defensive, and they are placed right below the participant whose action they attempt to counter, thus delaying their own turn.

Major actions include melee and ranged attacks, charges, and most actions aimed at significantly altering the opponent's state. Minor actions include readying a weapon, reloading a crossbow, or traversing the battlefield (distances are handled in abstract Zones). Reactions are the likes of parrying an attack, rolling behind cover, etc.

If an attack hits, roll two six-siders called Red and Black. Damage depends on the weapon wielded (light weapons deal the lowest of them, heavy the highest, and medium equal to Red). If Black is a 6, it also triggers the weapon’s special effect.

Damage is deducted from the target's hit points. When someone loses all of their hit points, they become Incapacitated. When an Incapacitated character takes Damage, they receive an Injury, that applies one of the following three conditions to the character: (1) scarred, (2) maimed, or (3) dead. Each can only be opted for only once.

Social Combat Redux

I recently posted a conversion of Courtney Campbell's social attack rules to the AS&SH system. However, after crunching some numbers it became apparent that such a system (no matter how baroque and appealing to me) would produce rather unbalanced results, so I decided to redo the maths.

My goal was to keep the rules simple while providing choice and strengthening class archetypes at the same time. I certainly like them better this way.

To-hit modifier = +1 per odd level + (INT or CHA modifier)
Social AC for monsters = 12 - morale - 1 per even HD
Social AC for players = 6 - 1 per odd level - (WIS or CHA modifier)
Social Damage = 1d8 + CHA modifier

Every player character may choose one of the four social attack types (Anger, Fear, Confusion, and Charm) as favoured, granting a +2 to-hit bonus (monsters usually do not get this bonus, but ultimately it is up to the Referee to judge). Furthermore, the following special rules apply:

• Using an appropriate spell grants +SpellLevel to-hit bonus and deals double damage.
• Assassins deal double Fear damage.
• Bards consider each social attack type favoured, and deal +1 damage per odd level.
• Berserkers are immune to social attacks while raging. (cf. Unbreakable Willpower).
• Druids and Scouts deal double damage against animals.
• Monks have a point of social damage reduction per level.
• Rangers deal double damage against otherworldly creatures.
• Thieves consider each social attack type favoured.
• Witches deal double Charm damage.

Five Kung-Fu Styles

I have been slowly (and I mean very slowly) working on a wuxia-inspired setting and OSR compatible rules. Below I present to you five kung-fu styles, one for each of the five different colours of chi. Also, some notes on the rules.

Social Combat in AS&SH

The following is a summary and conversion of the social combat rules found in Courtney Campbell's On the Non-player Character.

Characters may substitute one of their attacks (regardless of whether melee or missile) to make one of the following special attacks to deal non-lethal damage. Non-lethal damage is not deducted from one's current hit points but is totalled separately; once it exceeds 1/4 or 1/2 of the creature's current hit points, a Minor or Major effect takes place, respectively, depending on the attack type.

Attacks are resolved as follows:

• 1d20 - 4 (base penalty) + Intelligence modifier + Charisma modifier
• target AC equals either (10 - Wisdom score) or (10 - Morale) - 1 per 2 HD; creatures with animal intelligence have +4 AC bonus
• the attacker's Fighting Ability is a key factor; use your character's regular attack matrix to determine success
• successful attacks deal 1d8 points of non-lethal damage, plus the better of your Intelligence or Charisma modifier

N.B.: For the purposes of social combat, Intelligence modifier equals the number of extra languages, while Charisma modifier equals reaction bonus.

Marvel-esque Initiative and Turn Sequence

In OD&D, where it is basically only a roll with a d6, initiative is not much of a chore - but not really much fun either. In other games which use individual initiative, it certainly gives more random and individualised results but also increases the book-keeping factor. It was argued by Justin Alexander that initiative, as is presented, does not function as a seamless way of transitioning from the previous game structure (hexcrawl, dungeoncrawl, or else) to the combat structure; furthermore, the book-keeping it requires weakens the dynamics the outbreak of combat would present to the players (see this post and this post with the comment).

Trying to solve these problems, I came across the new Marvel game which uses a turn sequence system that I find very clever: after acting, it is the combatant's duty to choose who acts right after him. There are two important restrictions: (1) you cannot delay your action, you act when you are called, and (2) nobody may act again until everybody has acted in the round.

The game leaves to the GM to determine the first one to act depending on the situation; in a D&D-esque game, I would say the one who states his action the quickest may act first. By instantly resolving the first participant's action, we - all of a sudden - find ourselves in the combat structure.

Opinions? What possible disadvantages you can foresee regarding this approach? Do you think the benefits proposed above outweigh them?