d20 vs 2d6 Man to Man, flat vs curved distr.

[sepulchre]

Do the weapon modifiers vs. armor type in AD&D (d20) make up for the loss of a bell curve and weapon vs. armor type probability (2d6) [dagger: roll 6 vs. no armor, a 7 vs. leather or padded etc.] in the 'Man to Man' combat table in the 'Appendix B' of Chainmail?

Otherwise it seems that switching to a d20 platform merely offers a flatter distribution and large spread so as to allow for more armor types and more randomness to be involved and without a curved distribution, which seemed integral to describing the armor numerically in combat matrices as initially conceived. Any thoughts?

[Finarvyn]

I have a theory (which I've never seen proof to confirm, you understand) that the OD&D magic item tables from Men & Magic were designed to work with 2d6 while those from Greyhawk were designed to word with d20.

That could explain why the M&M tables have no weapons higher than +3 while GH takes them as high as +5.

It also explains where the rules say that dwarves are "the only characters able to fully employ the +3 Magic War Hammer", which sounds pretty cool until everyone else gets +5 weapons. After that, +3 weapons aren't so special. Unless the +3 was designed to fit a 2d6 attack model, in which case that's pretty impressive.

I also think that AC was originally designed to fit 2d6, if you had to roll AC or below for a hit instead of having all those different numbers based on weapon type. You'd have to roll 9 or less to hit an unarmored guy and if you had to roll a 2 to hit Plate+shield, that's pretty good protection.

I think that the common interpretation was that all of the weapons from both booklets matched the "alternate" (d20-based) combat system, and by the time AD&D was developed it was done to match Greyhawk anyway, so any attempt at 2d6 is long gone by the AD&D stage of the evolution.

Just me being a crackpot, I suppose....

[cooper]

I've been toying with the idea of 1d12 for the man to man/fantasy table attacks. It gives some use to the oft ignored d12, makes multiple attacks easier to read as you aren't rolling multiple dice per hit and allows you to throw multiple attacks at once.

[jacar]

Oct 16, 2010 5:13:18 GMT -6 Finarvyn said:

I have a theory (which I've never seen proof to confirm, you understand) that the OD&D magic item tables from Men & Magic were designed to work with 2d6 while those from Greyhawk were designed to word with d20.

That could explain why the M&M tables have no weapons higher than +3 while GH takes them as high as +5.

Actually, the reason the weapons were a max of +3 was because +3 was a huge boon on a single D6. Any more than that would practically gaurantee a hit! The M&M tables were a spawn of the Chainmail MtM tables but they were clearly written for "the alternate" system (AKA D20)

I also think that AC was originally designed to fit 2d6, if you had to roll AC or below for a hit instead of having all those different numbers based on weapon type. You'd have to roll 9 or less to hit an unarmored guy and if you had to roll a 2 to hit Plate+shield, that's pretty good protection.

As I understand it, Dave Arneson started as a naval gamer. The AC was a reflection of this. A low number say a 1st or 2nd rater in a sailing ship is a big and powerful ship. So AC is essentially the "Rate" of the armor. Plate armor and shield is the equivalent of a 2nd rater...ehm...so to speak.

I think that the common interpretation was that all of the weapons from both booklets matched the "alternate" (d20-based) combat system, and by the time AD&D was developed it was done to match Greyhawk anyway, so any attempt at 2d6 is long gone by the AD&D stage of the evolution.

Just me being a crackpot, I suppose....

Not being a crackpot at all. The game was clearly designed for players to play as they like! There are many systems and suggestions in Wilderness adventures and the MtM system from Chainmail was suggested for ship to ship actions of all things.

John

[jacar]

Oct 12, 2010 21:56:50 GMT -6 sepulchre said:

Do the weapon modifiers vs. armor type in AD&D (d20) make up for the loss of a bell curve and weapon vs. armor type probability (2d6) [dagger: roll 6 vs. no armor, a 7 vs. leather or padded etc.] in the 'Man to Man' combat table in the 'Appendix B' of Chainmail?

Otherwise it seems that switching to a d20 platform merely offers a flatter distribution and large spread so as to allow for more armor types and more randomness to be involved and without a curved distribution, which seemed integral to describing the armor numerically in combat matrices as initially conceived. Any thoughts?

Think of it this way. The D20 has an average roll of 10.5. However, as it is a linear system, the D20 allows frequent wild swings of fortune. You will just as likely roll a 10 as you will a 20. If you roll 1000s of time, you likely will have an average roll of around 10.5.

The 2D6 has an average roll of 7. As it is a bell curve, numbers will tend to fall in the 5-9 range. Wild swings of fortune will be few and far between. A character will tend to perform at a certain level (usually roll in the 7 range). If you rolled the dice even 100 times, your average roll will likely be in the 7 range.

So, I guess if you like more even performance, stick with 2D6 or even 3D6 for more granularity. If you like wild swings of foortune, go with a single die.

John

[cooper]

Thanks for the math breakdown Jacar.

Oct 16, 2010 5:13:18 GMT -6 Finarvyn said:

I have a theory (which I've never seen proof to confirm, you understand) that the OD&D magic item tables from Men & Magic were designed to work with 2d6 while those from Greyhawk were designed to word with d20.

That could explain why the M&M tables have no weapons higher than +3 while GH takes them as high as +5.

It also explains where the rules say that dwarves are "the only characters able to fully employ the +3 Magic War Hammer", which sounds pretty cool until everyone else gets +5 weapons. After that, +3 weapons aren't so special. Unless the +3 was designed to fit a 2d6 attack model, in which case that's pretty impressive.

I would agree with you. the +3 weapon goes with the -3 armor from the MtM rules. The magic weapon started as +1d6 on the 2d6 attack roll (average is 3...ok 3.5), when translated into the d20 attack matrix, Gygax must have just listed as +3. But I'm being redundant as I've been repeating myself in various threads on this very point so forgive me my pushiness. No surprise then that "super swords" like excalibur, or the Sword of Kas are +6 weapons, as the MtM rules talk about them giving +2d6 to the attack roll and +2 to the fantasy chart (let's assume, gygax balked at including the, "even +3!" weapons into d&d.

[aldarron]

Oct 19, 2010 19:27:43 GMT -6 jacar said:

As I understand it, Dave Arneson started as a naval gamer. The AC was a reflection of this. A low number say a 1st or 2nd rater in a sailing ship is a big and powerful ship. So AC is essentially the "Rate" of the armor. Plate armor and shield is the equivalent of a 2nd rater...ehm...so to speak.

John

Yeah, there is even a note on Dave Arnesons website along those lines, but after digging into this as deep as I could I've come to the conclusion that it's bunk. "Armor Class" is a concept Dave imported from the notes for his naval combat game, originally a civil war Ironclads game that morphed into Don't Give Up the Ship when he collaborated with Gygax on it. But there is no "1st class armor" in OD&D and the evidence from the FFC and early gamers indicates that Daves AC 1 was actually unarmored - with better AC going up, not down. The 2-9 best to worst thing seems to purely be a mathematical convenience - probably from Gygax - having to do with 2d6. Exactly why is still a question, but the scale itself it wasn't related to ships.

[sepulchre]

Finarvyn wrote:

I think that the common interpretation was that all of the weapons from both booklets matched the "alternate" (d20-based) combat system, and by the time AD&D was developed it was done to match Greyhawk anyway, so any attempt at 2d6 is long gone by the AD&D stage of the evolution.

That seems like a fair estimation.

Jacar wrote:

Finarvyn wrote:

I also think that AC was originally designed to fit 2d6, if you had to roll AC or below for a hit instead of having all those different numbers based on weapon type. You'd have to roll 9 or less to hit an unarmored guy and if you had to roll a 2 to hit Plate+shield, that's pretty good protection.

So, I guess if you like more even performance, stick with 2D6 or even 3D6 for more granularity. If you like wild swings of foortune, go with a single die.

I understand the correlation being 2d6 and the strong inclusion of chance with greater granularity (d20 or 3d6) as you both note. My concern here is how armor is conceived of mathematically beginning in Chainmail's 'man-to-man' combat.

In Chainmail's Appendix d there are 'all those different numbers' based on weapon type for landing a telling blow against a particular armor type. This matrices uses a bell curve (2d6) to determine an outcome. Heavy armor is difficult to hit:
a. based on the weapon employed
b. the distribution represented through a bell curve.
The move to the alternate combat system assumes different numbers based on weapon type mirroring Chainmail 'man-to-man' but does not keep with the curviture. The latter decision appears to me to undercut the protection afforded by heavier armor, unless the weapon vs. armor type modification in the alternate system assume this dual-gravity (A and B above). That is where my confusion lies.

[cooper]

Actually it goes even further in degrading the worth of heavy armor as--unlike the 2d6 combat matrix, the d20 combat matrix has heroes fighting with a 17 thac0.

In chainmail a hero would get 4 attacks per turn against normal men, but each of the 4 attacks had the same "thac0" if you will as a 0-level man. In dungeons and dragons the 4th level hero still gets 4 attacks, but now each of his 4 attacks have a greater chance of landing on the hapless plate armored men.

[sepulchre]

Cooper wrote:

In chainmail a hero would get 4 attacks per turn against normal men, but each of the 4 attacks had the same "thac0" if you will as a 0-level man. In dungeons and dragons the 4th level hero still gets 4 attacks, but now each of his 4 attacks have a greater chance of landing on the hapless plate armored men

.
Thanks Cooper! Indeed, armor thus seems degraded by the shift from Chainmail's bell curved distribution to the alternate combat system's linear curve in the following ways:
a. no longer based on just the weapon employed but also the
level of the wielder.
b. distribution represented through by a linear curve to
accomodate the greater spread.
...Though the alternate combat system borrows conceptually from Chainmail, the mathematical application of that concept is entirely different and thus it seems to me one becomes a very different game from the other.