BAB Comparison across D&D versions

[waysoftheearth]

No doubt this comparison has been done before, but I thought it interesting enough to share again...

What we have here is a table of fighter's BAB-equivalent attack modifiers across the various editions of D&D.

I didn't consider 4E because in that edition the BAB-equivalent is no longer the main source of a PC's attack modifier, nor is it derived from a PC's class.

I have ignored the change to armour ratings which were introduced with AD&D, and continued with later editions. Pre-AD&D, an unarmoured target was AC9, while plate and shield was AC2. Post-AD&D, an unarmoured target was AC10. By 3E, plate and shield would improve AC by 10 pips (from AC10 to AC0 in descending AC terms). However, none of this alters a fighter's BAB-equivalent, rather how often he might encounter opponents of better AC.

I have also excluded strength modifiers, however it is worth noticing that 18 strength adds a +3 attack modifier in all editions except for OD&D/Holmes (+0) and 3E (+4).

Fighter Level	OD&D	B/X	AD&D	2E	3E
1	+1	+1	+0	+0	+1
2	+1	+1	+0	+1	+2
3	+1	+1	+2	+2	+3
4	+3	+3	+2	+3	+4
5	+3	+3	+4	+4	+5
6	+3	+3	+4	+5	+6
7	+6	+5	+6	+6	+7
8	+6	+5	+6	+7	+8
9	+6	+5	+8	+8	+9
10	+8	+7	+8	+9	+10
11	+8	+7	+10	+10	+11
12	+8	+7	+10	+11	+12
13	+10	+9	+12	+12	+13
14	+10	+9	+12	+13	+14
15	+10	+9	+14	+14	+15
16	+13	+11	+14	+15	+16
Sum	97	86	112	120	136

I was surprised to find that B/X was actually the leanest edition with regard to BAB, although the introduction of strength modifiers of up to +3 would most likely have offset this difference (in comparison to OD&D) -- turning it to an advantage at low levels, where most actual play happens.

Notice how tough the 3rd level OD&D fighting man has to be, still working with his +1 attack modifier. Meanwhile an equivalent 3E fighter likely attacks at +4 to +7 (depending on his strength), a paltry 400% to +700% advantage!

[Morandir]

That's some pretty interesting stuff!

I'm not sure about your OD&D math though. Considering that AC 2 in descending is considered to be AC 17 in ascending, shouldn't the BAB for the first three levels be +0, since everyone needs a 17 to hit?

Mor

[benoist]

I'm surprised to see B/X behind OD&D on BAB.

One important thing to add to this analysis is the relative importance of magic weapons from one game to the next. In OD&D Magic Swords +1 are regarded as much more special items than they would be in a 3.x game. This affects the overall Attack Bonus output a fighter would have in the game.

[waysoftheearth]

Aug 10, 2009 22:10:11 GMT -6 Morandir said:

That's some pretty interesting stuff!

I'm not sure about your OD&D math though. Considering that AC 2 in descending is considered to be AC 17 in ascending, shouldn't the BAB for the first three levels be +0, since everyone needs a 17 to hit?

Mor

Hey Mor, now you've got me thinking twice about the way I calculated it...

I decided to myself that plate and shield (AC2) was the standard by which I could compare hit probabilities across the pre-3E additions.

Then all I did was figure out what a fighter would need to roll in order to hit AC0, being 2 pips more than required to hit a target in plate & shield.

Since a 1st level OD&D fighter needs to roll a 17 to hit AC2 (Men & Magic, page 19), it follows that he needs to roll a 19 to hit AC0.

Meanwhile, a 1st level AD&D fighter needs to roll an 18 to hit AC2 (DMG, page 74), so he needs to roll a 20 to hit AC0.

That's how I concluded that the 1st level OD&D fighting-man was actually one pip better off than his AD&D equivalent.

[waysoftheearth]

After some more thought, I decided that my initial assumption that plate and shield was the "gold standard" by which editions could be compared was flawed. The way armour is rated did change across editions, and this certainly influenced the numbers.

So, I have recalculated the table based on the fact that the unarmoured AC is that standard that doesn't change across editions. This turns out to be much easier, because in each edition there is a base, unarmoured AC against which normal mortals must roll a 10+ to hit. These are detailed here:

	OD&D	B/X	AD&D	2E	3E
Target AC	Desc AC9	Desc AC9	Desc AC10	Desc AC10	Asc AC10
Roll Required	10+	10+	10+	10+	10+

The result of this change is that OD&D (and B/X) fighting men are 1 pip worse off than they were in my previous calculations, just as Morandir suggested.

Fighter Level	OD&D	B/X	AD&D	2E	3E
1	+0	+0	+0	+0	+1
2	+0	+0	+0	+1	+2
3	+0	+0	+2	+2	+3
4	+2	+2	+2	+3	+4
5	+2	+2	+4	+4	+5
6	+2	+2	+4	+5	+6
7	+5	+4	+6	+6	+7
8	+5	+4	+6	+7	+8
9	+5	+4	+8	+8	+9
10	+7	+6	+8	+9	+10
11	+7	+6	+10	+10	+11
12	+7	+6	+10	+11	+12
13	+9	+8	+12	+12	+13
14	+9	+8	+12	+13	+14
15	+9	+8	+14	+14	+15
16	+12	+10	+14	+15	+16
Sum	81	70	112	120	136

That aside, I am still inclined to think that the first table of figures has some merit, simply because fighters are much more likely to encounter opponents of AC2 or better than they are to encounter opponents of AC10, which almost never happens.

Also, these new figures don't reflect that fact that an AD&D fighter actually needs to roll 1 pip higher than an OD&D fighter to hit the same AC. Meanwhile, Ogres and Orcs are AC 5 and 6, respectively, in both editions.

What I have learned is that this cross-edition comparison is even more complicated than I thought!

[Finarvyn]

Nice thread, Ways, and you get an EXALT for it becasue I love this kind of thing.

You're right that the AC issue between D&D and AD&D versions makes a direct comparrison somewhat tricky. I prefer the second chart (working from no armor up) to the first one (working from plate+shield down) because I think it more accurately reflects how BAB changes from level to level in the combat charts. Factoring in armor has its place, but I don't think it should be in a base-BAB comparrison.

Just my two coppers.

[Falconer]

What does BAB stand for? Strange it doesn't ring a bell.

[Finarvyn]

Aug 11, 2009 11:27:41 GMT -6 Falconer said:

What does BAB stand for? Strange it doesn't ring a bell.

It's a 3E term that means "basic attack bonus" or something like that, but I wouldn't expect that a 1E old-timer like you would have see it before, Falconer.

[Bard]

I think you made a mistake, B/X advancement system by class is exactly the same as the OD&D version... What is in the B/X column is not the B/X, but the BECMI ... I made some excel tables about this comparisons (with the cleric and magic user classes, and monsters by HD), without the 2e and 3e systems, but I put on the Labyrinth Lord, OSRIC and SW Whitebox progressions too. I try to upload it somewhere...

Edit: Here it is: demo.net.hu/kazar/THAC0.xls

[greyharp]

I'm glad you asked Falconer, I was scratching my head wondering what it stood for too.

[Bard]

Aug 11, 2009 0:40:23 GMT -6 waysoftheearth said:

That aside, I am still inclined to think that the first table of figures has some merit, simply because fighters are much more likely to encounter opponents of AC2 or better than they are to encounter opponents of AC10, which almost never happens.

Also, these new figures don't reflect that fact that an AD&D fighter actually needs to roll 1 pip higher than an OD&D fighter to hit the same AC. Meanwhile, Ogres and Orcs are AC 5 and 6, respectively, in both editions.

What I have learned is that this cross-edition comparison is even more complicated than I thought!

I think that the average AC a fighter will encounter, doesn't changed much between the editions. The unarmored man's AC changed to 10 from 9 in AD&D, but the plate mail + shield is the same AC 2. And the monsters AC too remained the same. The Monster Manual was written before the PHB, and the DMG... In the OD&D era... So I think this doesn't make much difference. I cannot speak about the second and third editions tho.

[Falconer]

Ah, okay. I'm not an old-timer, however, I haven't really ever played 3e, so it went over my head!

[Morandir]

Aug 11, 2009 0:40:23 GMT -6 waysoftheearth said:

Also, these new figures don't reflect that fact that an AD&D fighter actually needs to roll 1 pip higher than an OD&D fighter to hit the same AC. Meanwhile, Ogres and Orcs are AC 5 and 6, respectively, in both editions.

What I have learned is that this cross-edition comparison is even more complicated than I thought!

Well, as Bard said the 1e MM used the OD&D base AC of 9 rather than 10. Which leads to an interesting question: have any of you 1e users ever adjusted MM ACs to reflect this?

As for a 1e fighter, it's not really the same AC; it's the same armor, but the AC "bonus" is higher in 1e than in OD&D - in other words, plate + shield is worth more in 1e (8 points rather than 7). In all, it does make comparing things more difficult!

What's simpler is HP comparison between editions. If you've never looked at 3e monster manuals, the jump in hit points is staggering - yet weapon and spell damage did not increase to match. There's a reason a lot of 3e players look at Fireball with contempt. Just as an example, a Troll - which would have anywhere from 24 to 33 HPs in TSR D&D, on average (IIRC) - has 63 hit points in 3e, and something like 100 in 4e!

Mor

[Falconer]

Aug 11, 2009 15:00:23 GMT -6 Morandir said:

The 1e MM used the OD&D base AC of 9 rather than 10. Which leads to an interesting question: have any of you 1e users ever adjusted MM ACs to reflect this?

Nah, it's balanced fine, because if they're harder to hit because their AC is lower, they're also easier to finish off because their HP is lower (d8 per Greyhawk instead of d10 per Players Handbook). Basically, if you started updating the MM from Greyhawk to AD&D, where would you stop? There's too much to change, with no rewards, and you might accidentally screw things up. That is, it works fine how it is.

[waysoftheearth]

Aug 11, 2009 13:34:06 GMT -6 Bard said:

What is in the B/X column is not the B/X, but the BECMI

Ah, you are exactly right Bard. The second column of figures was from the BECMI edition, my mistake!

Apologies to those who aren't familiar with the 3E term Base Attack Bonus (or BAB for short). It is more-or-less a statistic used to replace all of the "Attack Matrix" tables of previous editions.

[Finarvyn]

Aug 11, 2009 15:00:23 GMT -6 Morandir said:

Well, as Bard said the 1e MM used the OD&D base AC of 9 rather than 10. Which leads to an interesting question: have any of you 1e users ever adjusted MM ACs to reflect this?

Maybe I'm a bad person, but I never bother to do much with this kind of thing. I figure if I'm off by one or two AC numbers it's not really a big deal, so even if I have handy a 2E MM I just tend to use the number in the book instead of worrying about a conversion.

The conversion is annoying anyway because it's not a straight "add one" or "subtract one" kind of thing, as I'm sure you all know. Having to convert if AC is in one range, and not convert if its in another, always seemed more clunky than just taking the number as stated.

[Morandir]

That makes perfect sense, and it's what I would do as well if I were in that situation; it was really just an idle question that popped into my head as I was typing.

Mor

[greyharp]

Aug 12, 2009 5:39:16 GMT -6 Finarvyn said:

Maybe I'm a bad person, but I never bother to do much with this kind of thing. I figure if I'm off by one or two AC numbers it's not really a big deal

Me neither and my player's have either never noticed or not cared.

[jjarvis]

Magic-User BAB comparissons for everyone-

M-U Level	OD&D	B/X	AD&D	2E	3E
1	+0	+0	-1	+0	+0
2	+0	+0	-1	+0	+1
3	+0	+0	-1	+0	+1
4	+0	+0	-1	+1	+2
5	+0	+0	-1	+1	+2
6	+2	+2	+1	+1	+3
7	+2	+2	+1	+2	+3
8	+2	+2	+1	+2	+4
9	+2	+2	+1	+2	+4
10	+2	+2	+1	+3	+5
11	+4	+4	+4	+3	+5
12	+4	+4	+4	+3	+6
13	+4	+4	+4	+4	+6
14	+4	+4	+4	+4	+7
15	+4	+4	+4	+4	+7
16	+6	+6	+7	+5	+8
Sum	xx	xx	xx	120	136

the AD&D MU fights as well as a 0 level man at levels 1-5 and that gets them a -1 on the chart above.

[Random]

Just a note, OD&D/Greyhawk fighters will almost always attack at an additional +1 compared to AD&D fighters.
The strength required for the bonus is 13 rather than 17.

At first level, AD&D fighters are thus (in general) 10% less likely to hit an unarmored opponent than OD&D (plus Greyhawk) fighters.

[Matthew]

Indeed; and it should also be noted that in first edition there is an optional rule for the fighter to advance in fighting ability as he does in second edition, so the difference between the two is something of an illusion in this instance. You might be interested in this comparison by edition and strength ratings: From Fighting-Man to Fighter. As an aside, BAB is a needless term that should have remained "fighting ability" (usually equal to fighter level).