How long have Ability Checks been in use?

[leg1on]

Hi All,

I've played in games with a few OD&D and AD&D DMs who resolved things on the fly with "roll a d20 vs your Dex" for example.

I like the method a lot.

Just wondering when was the first use of this idea. Where was it first published?

Thanks,

Legion

[Zenopus]

The earlier versions use multiple d6s, going back to Arneson. The Fantasy Trip may have popularized the idea. See here for a start:

zenopusarchives.blogspot.com/2013/09/3d6-stat-checks.html?m=1

I'm not sure when the d20 version was first used. It's definitely in B/X, not sure of any sources before that.

[Desparil]

The Moldvay Basic (1980/81) rules are the first version that I'm aware of to explicitly include it in the core rules. I know there was an overly complex version of ability checks that appeared in an issue of The Dragon. Someone with a better knowledge of all the old magazines might be able to pinpoint something more specific, be it The Dragon, Alarums & Excursions, or some other publication.

And of course, as Zenopus mentioned, there are plenty of primary sources attesting that Dave Arneson used a similar mechanic in his Blackmoor games, before the 'funny dice' were even a part of the game.

[asaki]

I'm pretty sure it's somewhere in the 2E rulebooks, as well (though B/X probably predates it).

[jeffb]

I think it's Dragon #1.1976.

roll percentile dice to come up with a die type multiplier. Then roll the die type and multiply by the ability score. then roll that or less a percentage.

e.x %die equals 50. check table- Multiplier die is a d8. roll D8. 4. 4xabilty score = % chance of success.

pulling numbers out of my butt, but that's the way it works.

[aldarron]

Sept 2, 2019 19:32:19 GMT -6 Zenopus said:

I'm not sure when the d20 version was first used...

Interesting question regarding d20 vs 3d6 ability saves. I think Arneson's quote in the FFC "First Fantasy Campaign (1977), "They must then avoid drowning (I ask them while they are falling what they are doing; if they are in Plate Armor, I give them a 1/10 chance of gelling It off in time; other must make a throw less than their dexterity rating..."

implies the use of a d20, but it isn't explicit, and I bet there's something in print in some fanzine from earlier.

[delta]

Another thing I just noticed in Arneson's FFC (p. 46):

A Sword's Intelligence is a very important feature and allows a great deal of variety in the Sword's operating ability allowing it to use it's powers to the utmost and indeed telling the owner that the Swords have these powers. In cases where the Sword's Intelligence would be of some importance, say, while lost in a maze, a die roll that scores less than the number of the Sword's Intelligence will allow it to act, where as a score equal to or higher than the Sword's Intellect will gain no reaction from the Sword.

(That was actually hard to get my fingers to type verbatim. What are there, like a dozen grammatical errors in those two sentences?)

[Finarvyn]

Sept 2, 2019 19:13:39 GMT -6 leg1on said:

Just wondering when was the first use of this idea. Where was it first published?

Possibly two very different answers to this. I've used some sort of stat check since around the time I started playing OD&D so that would be as early as '75 or '76, but I have no idea when it first hit print.

I probably got it as a "word of mouth" sort of thing, not necessarily part of a published article or product. For that kind of thing I often have no clue where the rule came from originally. Things like "double damage on a natural 20" fall into this category, as does "binding wounds for a d4 healing after combat" (actually, this may have been a JG thing). Some of these rules have been around so long that I would SWEAR have to be in the OD&D rulebook somewhere, but then I search and it's not there.

[countingwizard]

I think it would be cool as hell to document each type of random roll used by referees in D&D, and the approximate year. I mean my running list is something like:

1d20 equal or over target number to hit AC, modified by attacker level.
1d20 equal or over saving throw, modified by character level.
d6 roll to determine listening, forcing door, monster encounter, getting lost, surprise, some thief skills.
1d100 equal or under attribute score to succeed at action (sometimes multiple characters can add together).
3d6 equal or under attribute score to succeed at action.
2d6 to determine reaction, morale, undead turning, some thief skills.
1 or 2 on a d6 equals default odds of thing happening, generally applied.
1 on a d6 equals odds that rare thing happens, generally applied.

[derv]

It's easy to get tunnel vision with mechanics like this. It's especially true if your primary roleplaying experience has been D&D with all it's trappings- it's common monikers and labels. There's six abilities, right? Strictly speaking I guess we would say yes. But, no, not really. OD&D establishes others and they are tested. One is this idea of Fighting Ability. Another is Special Abilities couched with the Saving Throw.

Any way, I've been preparing to run a war game by Osprey called Outremer: Faith & Blood. It's a skirmish ruleset for the Crusades. It has this interesting way of using a figures stats and die rolls in relation to an opponents ability scores. So, it kind of reminded me of this thread. Usually when we talk about ability checks we are thinking d20 = or < than one of the PC's own six ability score or some such variation on this theme. Sometimes it's worthwhile to think outside the box.

edit: had to run an errand

Okay, so thinking outside the box, in 1975 Ken St. Andre published T&T with the help of Flying Buffalo (RIP Rick). Ken was not a war gamer. The games core mechanic revolves around ability based saving rolls (SR). Two games spin off of T&T- Monsters! Monsters! (1976) and Mercenaries, Spies, and Private Eyes (1983). Both retain this core mechanic. Since Blackmoor was mentioned I thought some might find it interesting that Arneson wrote a supplement for MSPE called Mugshots: The Case of the Pacific Clipper. You never hear much about Arnesons relation with FB and I always wonder what his thoughts were on MSPE.

[leg1on]

Thanks for all the replies.

What I like most about d20 vs stat is that because ability scores run from 3-18 a d20 roll bookends that range with 2 slots on either end. So it's always possible for a guy with 3 Dex to succeed and it's always possible for a guy with 18 Dex to fail.

It's really quite elegant.

And, can someone please tell me on what page it is in Moldvay Basic? I've looked and can't find it.

Thanks again.

[delta]

Sept 14, 2019 15:59:05 GMT -6 leg1on said:

And, can someone please tell me on what page it is in Moldvay Basic? I've looked and can't find it.

Page B60, in the section "Dungeon Mastering as a Fine Art", under the heading "There's always a chance."

This overall final section seems to have a bunch of Moldvay-specific recommendations which are either additions or variations from the Original D&D rules (and very solid and well-considered ones, I might add). For example, this section also recommends using miniatures at a 1" = 5' scale (p. B61), which actually contradicts the previously-given OD&D-standard of 1" = 10' (p. B19).

[captainjapan]

Sept 2, 2019 19:13:39 GMT -6 leg1on said:

Hi All,

I've played in games with a few OD&D and AD&D DMs who resolved things on the fly with "roll a d20 vs your Dex" for example.

I like the method a lot.

Just wondering when was the first use of this idea. Where was it first published?

Thanks,

Legion

If I had to guess, I'd say the first published use of that attribute check was when Steve Perrin printed his D&D combat sequence in All the World's Monsters 2. He was collecting house rules in northern CA around 1976 and included a Dexterity check to use for various tasks (dodging/ casting/ etc.) that weren't covered in the rules. In his system, every point of dexterity became a 5% cumulative chance of success. Roll under on percentile. Dungeons & Dragons wouldn't have anything like this until 1978, when the AD&D PHB came out where you had to use it to save vs. falling into your own hole, using the 'Dig' spell.  

[leg1on]

Thanks delta and captainjapan!

The other thing I really like about doing this is that it makes the six ability scores applicable across the board.

Can you swim that distance under those circs? Pick two of the three physicals, average them, flip a coin for rounding if nec (I like to embed luck), roll a d20.

Perception? Pick two of the three mentals (or morals or spirituals; whatever you call them), ditto, roll that die.

Impose a penalty for difficulty or time pressure, apply a bonus for skill or level, and Boccob's yer uncle!

[Finarvyn]

Sept 11, 2019 20:36:48 GMT -6 Piper said:

I recall using them back in 1975 but I can’t remember for the life of me where I got the idea.

And honestly that's half of my problem. I experimented with a lot of rules back in the day, particularly early on, but I have no idea where I got my inspiration or if I made something up independent of someone else.

Outside of our small gaming group, communication was very limited but I suppose I could try to reconstruct some of my thinking by re-reading those early sources. For me, they start with OD&D and supplements, then extend to SR and the early Dragon magazines (starting with #4, I think, since my friend subscribed and issues 1-3 were sold out or something), add in the EPT boxed set, plus early Judges Guild materials (but early on only the subscription stuff since I didn't have the money to buy a lot of extras at that time). Most of my early inspiration would have come from those printed sources, and if something isn't in there we probably made it up. By the 1980-81 school year I finally encountered another game group at the local university, so that was a potential source of new ideas, but that's well after most of my players had moved on to AD&D and making stuff up was less encouraged then. (I would guess that 1975-1978 were my most creative times. The publication of AD&D's PH and DMG caused our group to create less and follow more.)

An example of parallel discovery for me would be ascending AC. I disliked regular AC from the start and sometime early on (prior to AD&D) I flipped the thing over with "Armor Rating" that started with 0 for no armor and went up as armor got better. (So 2 for leather, 4 for chain, 6 for plate.) Then I applied it to an equation where you would roll a d20 (of course we didn't have dx notion for dice then) and try to roll above AR+10. In retrospect, 3E's version was a lot nicer than mine but they were nearly identical in effect. So a rule that I created 20 years prior to when I saw it in print (I assume, as I can't recall any other ascending AC rule prior to 3E) looks totally different because of the vocabulary and such that we had at the time. I certainly wouldn't try to take credit for this kind of thing because I'm sure that others did this stuff, too. THAC0 looks different from ascending AC, but at the root it's still an attempt to convert a chart into an equation. (Honestly, I still don't "get" THAC0. I've never used it and never really took the time to understand it.)

I did a similar thing with a "thief action" where I took the thief percent tables, converted into d20 tables, then converted it into a single number (that varies with thief level) with a bonus to the roll depending upon the type of action being performed. It's one of the rules I was going to put into my WB rules, but then it was decided that thief wouldn't be a part of that particular rules set. I assume that folks do that sort of stuff all the time, yet when I did it I was doing it for the first time as far as I knew.

For Blackmoor you'll see guys like Greg Svenson saying stuff like, "well, so-and-so went into the army in 19xx and so it must have been before/after..." or perhaps, "well so-and-so was playing when it happened and he left the group in..." and without that sort of reference how would you really remember the date? I'm sure that this is why so many of the early dates are confusing nearly 50 years later.

I guess my main point is that determining the date for anything that long ago is hard unless...
(1) You can point to a published product that has that something in it, or
(2) You can find some important defining event where you can say "it is before or after THIS."

Sorry. This post is a lot longer than I had planned.

[delta]

Sept 15, 2019 5:08:13 GMT -6 Finarvyn said:

An example of parallel discovery for me would be ascending AC. I disliked regular AC from the start and sometime early on (prior to AD&D) I flipped the thing over with "Armor Rating" that started with 0 for no armor and went up as armor got better. (So 2 for leather, 4 for chain, 6 for plate.) Then I applied it to an equation where you would roll a d20 (of course we didn't have dx notion for dice then) and try to roll above AR+10. In retrospect, 3E's version was a lot nicer than mine but they were nearly identical in effect. So a rule that I created 20 years prior to when I saw it in print (I assume, as I can't recall any other ascending AC rule prior to 3E) looks totally different because of the vocabulary and such that we had at the time. I certainly wouldn't try to take credit for this kind of thing because I'm sure that others did this stuff, too. THAC0 looks different from ascending AC, but at the root it's still an attempt to convert a chart into an equation. (Honestly, I still don't "get" THAC0. I've never used it and never really took the time to understand it.)

That's a very nice data point, glad you shared it!

Likewise, I independently came to the "attack bonus" method for combat in the mid-90's, several years before it appeared officially in 3E D&D. It's among the things that made me fall hard for 3E as being an apparently very clever system (at first).

Also I'd say it's highly unfortunate that the fan-invention of THACO was set up the way it was initially; it's ultimately a series of two, large, compounded reverse-subtractions which is an almost unbelievable mess when you think about it. If you just note that the two subtractions cancel out then you get a single-digit number to add instead, equated simply to fighter/monster level. Very similar to your "missed it by that much" rule for reversed AC.

[Zenopus]

Another type of early ability check is the "static" check where you either make it or don't depending on your score.

Holmes uses this twice in Room H of the Sample Dungeon in the Basic rulebook (1977).

If a PC falls in the water, they are swept away unless they have a Strength of 15 or higher. If swept away they are unhurt if they have a Con of 12, otherwise they have a 50% chance of taking 1 die of drownin damage before being deposited on a beach in the next room.

Another variant is seen in Room A, where the sleeping gas knocks you out for 1d6 rounds, "subtracting a 1 if the character has a high constitution" (number not specified, but page 5 says scores of 9-12 are average).

[Desparil]

Sept 15, 2019 12:46:40 GMT -6 Zenopus said:

Another type of early ability check is the "static" check where you either make it or don't depending on your score.

Holmes uses this twice in Room H of the Sample Dungeon in the Basic rulebook (1977).

If a PC falls in the water, they are swept away unless they have a Strength of 15 or higher. If swept away they are unhurt if they have a Con of 12, otherwise they have a 50% chance of taking 1 die of drownin damage before being deposited on a beach in the next room.

Another variant is seen in Room A, where the sleeping gas knocks you out for 1d6 rounds, "subtracting a 1 if the character has a high constitution" (number not specified, but page 5 says scores of 9-12 are average).

I don't have the time to hunt them down right now, but I can recall a few other interesting oddities where a similar thing was done with doors - instead of a normal Open Doors roll, a module might specify "three characters working together with a combined total of 40 Strength are needed to open this door," or something like that.

Finarvyn said:
(Honestly, I still don't "get" THAC0. I've never used it and never really took the time to understand it.)

There's honestly not much to "get" - THAC0 is just the minimum number you need to roll to hit AC 0, and for targets with some other armor class you subtract the AC from the target number. So if your THAC0 is 19 and your target is AC 9, you have to roll a 19 - 9 = 10 or better to hit.

[Deleted]

As a related question, in Runequest there is something called a Resistance Table that is used to compare ability scores from two characters competing. If you're tied it's a 50%, plus 5% for each point you have over your opponent. It's used for things like testing Strength vs Strength, the classic example being arm wrestling. I know that the guys who made Runequest were D&D players, but has anyone seen any chart like this for use in D&D.

You could, of course, use it straight but I'm wondering if the idea for this chart stems from D&D or was it created for Runequest.

If not, how are DMs supposed to test one ability against another?

[captainjapan]

Sept 15, 2019 14:14:27 GMT -6 @hedgehobbit said:

As a related question, in Runequest there is something called a Resistance Table that is used to compare ability scores from two characters competing. If you're tied it's a 50%, plus 5% for each point you have over your opponent. It's used for things like testing Strength vs Strength, the classic example being arm wrestling. I know that the guys who made Runequest were D&D players, but has anyone seen any chart like this for use in D&D.

You could, of course, use it straight but I'm wondering if the idea for this chart stems from D&D or was it created for Runequest.

If not, how are DMs supposed to test one ability against another?

Sven Lugar, who drew up the original resistance table for Runequest says that the 'only' reason it was included was because Perrin's playtesters didn't want to do the 50 + 5%/point diff. math themselves.

[asaki]

Sept 14, 2019 16:20:36 GMT -6 delta said:

For example, this section also recommends using miniatures at a 1" = 5' scale (p. B61), which actually contradicts the previously-given OD&D-standard of 1" = 10' (p. B19).

I always do this. You can fit more than one character in a 10-foot square, but it's really hard to fit more than one miniature into a 1-inch square.

[delta]

Sept 16, 2019 4:30:58 GMT -6 asaki said:

Sept 14, 2019 16:20:36 GMT -6 delta said:

For example, this section also recommends using miniatures at a 1" = 5' scale (p. B61), which actually contradicts the previously-given OD&D-standard of 1" = 10' (p. B19).

I always do this. You can fit more than one character in a 10-foot square, but it's really hard to fit more than one miniature into a 1-inch square.

I agree. I've had people argue the opposite against me, though. "We didn't care about that", and so forth.

[asaki]

I've played too many games (one last Friday) where the characters are in a hallway that's only one square wide, and the players end up doing this stupid "one person at a time" dance >_<

Unfortunately, Friday's game specified that the hallways were only five foot wide...seems like poor game design to me, but what do I know?

[Deleted]

Sept 16, 2019 4:30:58 GMT -6 asaki said:

I always do this. You can fit more than one character in a 10-foot square, but it's really hard to fit more than one miniature into a 1-inch square.

Miniatures today are significantly larger than miniatures from the 70s. Back then, it was possible to fit three miniatures in a 1" space. Tight but doable.

[Desparil]

Sept 17, 2019 6:09:52 GMT -6 @hedgehobbit said:

Sept 16, 2019 4:30:58 GMT -6 asaki said:

I always do this. You can fit more than one character in a 10-foot square, but it's really hard to fit more than one miniature into a 1-inch square.

Miniatures today are significantly larger than miniatures from the 70s. Back then, it was possible to fit three miniatures in a 1" space. Tight but doable.

My oldest minis are from the 80's, but I've actually been led to believe that a lot of the minis that Gygax owned were actually the even larger 40 mm type - whereas nowadays somewhere between 25 mm and 30 mm seems standard.