I must create a system, or be enslaved by another man's. I will not reason and compare: my business is to create.

- William Blake

Monday, June 05, 2023


The "weapon versus armor" table (page 37) is probably one of the least used in the PHB, as we've seen. However, it contains some cool ideas. Basically, it makes weapons more distinct and more balanced. And, well, much cooler. 

Notice that the table contains not only "weapon versus armor", but also length, space required and speed factor. The first two are probably ignored as often as weapon versus armor, but are quite simple and easy to understand. Speed factor, however, is intertwined with the cryptic AD&D initiative rules. It ultimately means that you can attack first and more often with a fast weapon (the lower the speed factor, the quicker the weapon). 

Finally, certain weapons can dismount and disarm, and weapons deal differnte damge agasint large opponents. We will leave that for another time.

Could we use this information for something cool in our B/X games? Or at least try to reduce it to B/X levels of complexity? 

I think we can! 

First, take a look at the table. I added color, an "average" column for the weapon versus armor values, and repeated the speed column by its side to show something that should be more or less obvious: speed in inversely proportional to to-hit bonuses (the blue/red colors almost never match in these columns). This means heavier/slower weapons hit more often, even if they attack less often. 

Here's the same table with some outliers eliminated (fists, staves, clubs, an whatever the awl pike is) to increase contrast.

Now speed is reduced to 1-10 and to-hit bonuses are reduced to -3 to +3 (but the average for each weapon is just -1 to +2).

I wouldn't want to check a table for every attack, nor use the AD&D initiative system in my games. But what if we only had one single number per weapon, meaning both "speed" and "strength against armor"? They'd need to be inversely proportional. 

Here is my fix: When you roll a natural 20, your deal normal damage and roll again to see if your attack was a brutal hit. This is resolved as a regular attack, but with a bonus equal to your speed factor

Hit or miss, you can now make another attack ("fast hit") against the same target or an adjacent foe, IF the number on the d20 is GREATER than your speed factor, but with no bonus.

In practice, this means someone using a heavy weapon deals double damage on a natural 20 very often, regardless of armor. On the other hand, quick weapons often get another attack - which is particularly deadly if you are unarmored.

Example: Aleena gets a natural 20 using a mace (SF 6). She rolls again with a +6 bonus (which makes a huge difference against heavy armor), potentially damaging the original target even further. AND she gets a second attack if her roll is higher than 6. 

Example 2: a lowly bandit attacks a knight in plate (AC 3) with a dagger. He gets a natural 20, and can roll again (with a +2 bonus), and very likely attack again (no bonus). Still, his chances of hitting are very low. Had the target been unarmored, he would have a decent chance of doubling or tripling the original damage. 

I do not mean necessarily that I would use AD&D numbers - I should probably come up with my own and maybe even create some exceptions. But the procedure looks sound, it seems to achieve what I intended: 

- Weapons are distinct in both "speed" and "strength against armor". 
- Every weapon can potentially have its own niche. 
- A single digit is added to weapon stats. 
- Even that single digit can be safely ignored 95% of the time. 
- You can assign any number to speed factor on the run, not only because the 1-10 skill is intuitive, but also because it is fair (every number has its pros and cons).
- You can easily fit this in the Dark Fantasy Basic scheme of t/s/m/l/g weapons, by assigning SF 2/4/6/8/10 (plus one or minus one for maces, spears, etc.).
- Crits are meaningful, but not enough to be "too deadly". Doubling damage is rare if you're wearing armor, tripling it very unlikely - and memorable!

Now let's see some numbers.

Table 1 calculates the chances of a brutal hit (we NEED to do something cool with those cases that beat 100%, of course - they should probably cleave or carry over somehow).

Table 2 calculates the chances of a quick hit (THAC0 19 means you usually hit 20% of the time against AC 2; SF 1 means you get a second attack 95% of the time, multiply both to get 19%, etc.).

Table 3 is just the sum of both tables. It illustrates that, while slower weapons are better overall, the difference is much more significant with low AC - AND low AC affects fast weapons much more. Exactly as we wanted!

I love these tables - they remind me of FASERIP/Tagmar. But here, they are just illustrations - you do not need to look at any tables to play the game, just a single number per weapon!

So, the dagger (SF 2) has about 30% of a brutal hit against AC 2, AND a 14% chance of landing a fast hit. The chance of triple damage (assuming a new attack against the same target) is very low (I think less than 5%, but it isn`t easy to calculate, since a successful roll increases both chances). But against AC 10 the chances are 70% for a brutal hit and 52% for a fast hit.

A two-handed sword has 70% chance of a brutal hit against AC 2, plus a 8% chance of  fast hit. Against unarmored foes, a brutal hit is certain, and a fast hit happens 30% of the time.

The chance of dealing triple damage against unarmored foes is similar for both weapons.

The exact numbers are not most the important part, of course. We are here for the FUN: swinging a huge weapon that crushes your enemies even inside armor, or stabbing your unarmored foes repeatedly with a dagger.

Of course I want these to be multipurpose mechanics. You can use the same number for all kinds of things - initiative, backstabbing, maybe weapon size/length ("weapon size" sounds better than "speed factor" BTW - or maybe "leverage"?), etc. 

But this is fine tuning - for now, I'm very happy with the general idea.

In the next post about this subject, I'll try to give you a table that is ready to use with B/X...


  1. I've never seen speed factor and weapons vs armor tables compared like this - very eye opening. I've seen many attempts to "fix" the lack of differentiating traits for d&d weapons, usually by giving the weapon some special thing. AD&D seems to have nailed it the first time around, though you have to use segments and weapons vs armor tables to get there. The basic tradeoff of either hitting more consistently vs armor or attacking faster (more often?) feels like what everyone attempts to do.

    Under the hood, there's some pretty genius systems in AD&D, along with some very strange ones - it can be hard to tell which is which at a glance.

    1. I agree. It is amazing how well these things work - they are just too cumbersome to use in practice.

  2. Why do people have such a hard time with this concept?
    "I wouldn't want to check a table for every attack"

    Of course not. There's a space on the AD&D character sheet for writing in the weapon versus armor class modifier. You look it up one time and write it in the little boxes.

    And if something comes up and you do need to consult the chart? It's printed right on the official dungeon master's screen for easy reference.

    All of the eleven and twelve year olds that I played with as a kid figured it out without any trouble.

    1. I believe you - I was playing GURPS and MERP before this age and I did not think they were complicated either.

      However, while I'm actively looking for AD&D stuff to add to my games, I prefer something simpler nowadays (B/X).

      Yes, you could in theory write this down in your sheet, if you had a place for every weapon (I'm not even sure official AD&D sheets had room for speed, length, space - there are more than 10 numbers for each single weapon). And of course you'd need the GM screen, because NPCs.

      This is still too much hassle for me, personally, and it only solves half the equation - since speed and initiative are also very complex, to the point that it's simplification (ADDICT) is too much for me to handle - remember, I'm coming from this form a B/X perspective.

      So, while AD&D can be a fine game exactly as written , what I'm looking for is something slightly crunchier than B/X - or small crunchy bits to add to B/X.

      Of course, anyone can use AD&D is written, including this table - which apparently not even Gygax did - although I still think most people simply ignore it.

  3. A couple thoughts on implementing a very simple version of speed factor:

    Assuming side based, d6 vs d6 initiative:

    - large weapons win initiative ties (melee attacks resolved before other side) when closing to melee (polearm, battle axe, two handed sword, lance, staff, maybe spear, etc)
    - small weapons win initiative ties (melee attacks resolved before other side) when melee is already joined (dagger, short sword, club, etc)

    This would require running ties as "both sides act simultaneously" which itself requires both sides declare actions at the beginning of round, but that's not an issue.

    1. This is perfect! I hope you don't mind if I use something very similar in a future post! :D

    2. Sure, go for it. Glad you like it.

      I think the frequency of occurrence (1 in 6 combat rounds will be tied) is good - keeps the rule from being too rare and thus forgotten.

      The "bonus" for having the right weapon - resolving your attack first - seems pretty important vs low-HD monsters where hitting first can kill and thus prevent retaliation. It may be less of a factor when HD's get higher.

    3. Yes, this is great. I might switch initiative to 1d10 to do an extra attack with certain weapons... let's see.

    4. Interesting - getting an extra attack is a much "meatier" reward for having the right weapon for the moment than getting to resolve your attacks first. Likely this bigger incentive will encourage more weapon consideration by players.

      It does feel a little odd to me to get such a big spike in potential damage based on a tie - emotionally players should be hoping to win initiative.

      Also B/X combat is pretty swingy already - I'm not sure I want players to close in on a group of 5 orcs with spears, tie on init and eat 10 attacks.

      You could also scratch the whole interaction with the initiative system and say something along the lines of "long weapons get +1 damage while closing to melee, short weapons get +1 damage while already in melee" or something like that.

    5. Well, It certainly requires some fine tuning, But it is not as extreme as it looks.

      Not much different than being surprised and losing initiative, for example.

      But yeah, some reflection and playtesting required.

  4. The initiative system is completely Byzantine and I haven't used it since 1983. I modified a system out of Dragon magazine and I've been using it ever since.
    The official character sheets had space for about five different weapons and all of the various statistics. After a while you basically had all of the common weapons memorized.

    I know what you mean about adding crunch, I'm currently running a game on Blueholme and it definitely needs a little ooomph.

    1. Exactly! There is certainly a "goldilocks zone" somewhere between basic and advanced!