OD&D Recap

Now that I've spent some significant time thinking about the OD&D rules (and writing up my house rules, below), I do think that OD&D provides perhaps the best basis for a hobbyist to use as a platform for their own, personalized version of the game. However, if you approach the "little white box" for the first time you may be surprised by a few things -- here are the most significant things I felt compelled to "fix" in my Original Edition Delta:

1. Abilities do not modify actions. Generally speaking, while OD&D has the classic 6 abilities, in the main the idea that they should be used to modify actions in the game had not yet been invented. The first 3 (Str, Int, Wis) do nothing except modify XP awards (respectively for the initial 3 classes: Ftr, M-U, Clr). The latter 3 (Con, Dex, Cha) give at most a +/-1 modifier to certain rolls (Con: hit points; Dex: missile fire; Cha: hireling loyalty).

This was rapidly changed by EGG in Supplement I: Greyhawk, where all of the abilities received some sort of action modifiers (identical to what we know from AD&D). However, it's a fair claim that EGG went off the deep end here, with extensive tablature lacking any core system for the DM to remember mentally. Every system since that time has responded by seeking to standardize the various ability modifiers (Moldvay Basic, 3E D&D, Castles & Crusades, my own OED, etc.)

2. Racial benefits are rather scattershot. The benefits accrued to different races (dwarf, elf, halfling) are a somewhat complicated melange of abilities in the OD&D player's book, references back to Chainmail, and variations on abilities indicated in the OD&D monster booklet. You have to hunt a pick and do some interpolation (as from Chainmail) to figure out exactly how these abilities should fit into your D&D game. Dwarf trap-finding, elven combat advantages, and halfling missile fire are not given any numbers in the OD&D books themselves. Furthermore, I feel that the lack of a core system created a proliferation of later add-on abilities, which became highly burdensome to track in AD&D or 3E D&D. The same can be said for the elven multi-class ability.

Again, Supplement I: Greyhawk felt compelled to quickly address these issues. Multi-classing was expanded and formalized (as seen in AD&D), not with complete success. Racial abilities were given additional detail (some in errata), again in ways that were not totally balanced. This is one of the things I massaged in OED; selecting from a limited number useful, relevant, and memorable racial abilities.

3. Weapon effects are not distinguished. In the classic OD&D system, no weapon is different from any other weapon; they all strike at the same rate, with the same to-hit chances, for the same 1d6 damage. If you want different weapon effects (first-strike, chance-to-hit), then you have to make use of the earlier Chainmail system (which was apparently the default assumption for OD&D).

At the risk of sounding repetitive, Supplement I: Greyhawk again saw this as a need clearly requiring redress, and provided a variant system giving different damage, to-hit chances, required space limits, and other details to the different weapon types. Personally, I judge this as a well-meaning project but with limited success; similar to the Greyhawk ability modifiers, this material was perhaps too cumbersome for convenient use (what with separate damage rates for small-versus-large targets, difficult-to-adjudicate space requirements, and an enormous table of weapon-vs-armor adjustment minutiae). With Supplement II this project further expanded into a complete hit-locations system which pretty much collapsed under its own weight. Almost all versions of D&D since have felt compelled to pare down these rules (no size differentiation; no weapon-vs-AC matrix, etc.) In OED I took the Greyhawk project as inspiration and again trimmed it down to its usable kernel.

4. Table-based functions are the rule. Now we get to points that EGG never distanced himself from. All forms of classic D&D (OD&D, AD&D, Holmes/Moldvay Basic, etc.) are largely table-based in adjudicating combat, saves, class hit dice, thief skills, etc. This creates a bit of a slow-down in play as the DM has to look up each of these cross-referenced items. It's additionally odd because in most cases there's a simple one-line formula that could be used to replace the entire table (for combat, it's d20 + fighter level/Hit Dice + AC >= 20, etc.)

Various camps did finally see this simpler formulation, and included things like THACO in the AD&D DMG, or the d20 core mechanic in 3E (albeit at the expense of every target of any action in the world requiring a DC listing). I am greatly in favor of the speed-up gained from a simple formulation, so of course that's what I use in all my games, including the OED.

5. Encumbrance is at the wrong granularity. I've railed about this for a long time, and it's a fundamental error that no version of D&D has ever corrected to date. In OD&D, EGG specified weights in coins (1/10 of a pound), so to find encumbrance you have to add up numbers in the hundreds and thousands of units -- ultimately it requires a calculator in hand, and it's highly cumbersome. 3E uses pounds, and it's little different (still adding scores or hundreds of units). Legions of us have simply ignored encumbrance for decades because of this aggravation.

What you really need is a system whose scale requires adding numbers up to, say, 10 or 20 at most, which we can all do immediately in our heads without a calculating device (on the same scale as the D&D system for class levels, ability scores, hit dice, damage, to-hit scores, saves, and so forth). Basically any granularity on the order of about 10-pound units would suffice. Most fortuitously, there is a real-life Imperial unit of the "stone" (14 pounds) which both satisfies this requirement perfectly, and at the same time provides additional in-world color. All you need is for the core rules to specify weights in "stone" and the whole encumbrance system becomes trivially easy to sum and adjudicate. (See previously here.)

6. Combat scale and sequence are unclear. Perhaps the most troubling oversight in OD&D, the exact relation of distance, time, and actions in a round lives in a hazy gray zone somewhere between Chainmail, OD&D, and AD&D. The OD&D distance scale is specified as 10 feet (a briefly-considered switch from Chainmail's 10 yards), which fails to physically fit miniature figures in the assessed space (resulting in the tortured explanation early in the AD&D DMG). The OD&D time scale is described as "fast and furious" at 1 round per minute, which is not really "fast and furious" at all (and again results in a labored and unconvincing justification at the start of the combat chapter in the AD&D DMG).

Here, the 3E D&D game finally made the required fix, clearly setting the distance scale at 1" = 5' (basically the same as miniature figure scale), and round length at a fraction of a minute each (6 seconds, whereas I prefer 10 seconds after some analysis of real-life archery speeds and the like). Now we finally have "fast and furious" combat, which was an admirable goal from the start. This I've carried into OED, along with additional clarifications gleaned from how the Chainmail and Swords & Spells combat sequences were intended to function.


  1. One easy way to get a version of "OD&D" that does include these changes is to download Swords & Wizardry. The designers of that must have had a list of gripes very similar (if not identical) to your own.

  2. I downloaded your 'Delta Ammendment' and like them very much across the board. The only house rule I might make is weapons (d6-1,d6,d6+1).

  3. I love this kind of topic.

    I like the idea of the use of 'stone' as a measure but the 1:14 conversion ratio just kills the idea for me, and defeats the purpose of using non-pound units to keep the arithmetic easy. I'd just use a new unit like an "enc" and set it at 1:10. This also allows a gray area where "enc" != weight.

    OTOH the 1:14 ratio might encourage a more handwavy guesstimation style of enc tracking which is what I would want, hm. I just don't want to be stuck there going "uhh..." trying to divide by 14 in my head. I suppose one could divide by 10 and call it good.

    A problem I have with a 5' scale is that it's more granularity than I want for ranges, hallway lengths and widths and so forth---which can make mapping annoying for everyone---but then I'm an anti-miniatures guy so I can't weigh the benefits.

  4. Nice post!

    I’m horrible at arithmetic, so formulas actually slow the game down more than tables when I’m running.

    Actually, I’m a big fan of tables because they have the potential to make complex formulas fast. I was surprised at how fast even the Rolemaster Arms Law tables were in play. Unfortunately, D&D rarely took advantage of this.

  5. I just don't want to be stuck there going "uhh..." trying to divide by 14 in my head.

    Much like the metric system, proper usage would avoid ever having to "divide by 14". Weights would be stipulated at the proper units in the core rules (like my OED).

    To paraphrase XKCD, "The key to converting to Imperial is establishing new reference points. When you hear '4 stone' instead of thinking 'that's 56 pounds' you should think, 'that's heavy enough to slow down an average-strength person.'"


  6. One easy way to get a version of "OD&D" that does include these changes is to download Swords & Wizardry.

    I would have to disagree. I don't like S&W's (1) ability modifiers, (2) lack of codification for racial abilities (like dwarf trapfinding), (3) weapon damage in non-straight dice increments, (4) table-based combat, (5) encumbrance in pounds, or (6) 1-minute long combat rounds.

    There's other stuff in S&W that makes it not for me (clerics, no thieves; races locked into certain classes), but on the specific points mentioned here S&W is not to my liking in each and every case.

  7. K Bailey -- I've switched to STONE enc as well. The way I rationalize it thusly:

    3 x One Handed Items = 1 stone
    6 x Light Items = 1 stone
    1 stone = ~15 lbs (15 is much faster for mental math than 14)\
    2 stone = 1 quarter, i.e., about as much as you can move with comfortably
    8 stone = 1 hundredweight, i.e., about as much as you can lug, slowly

    On your standard character sheet, you can go ahead and draw a grid about 6 squares wide and 2 squares tall. This represents a character's backpack of around 2 stone enc. Another grid 6 x 1 represents a belt pouch or two. A final grid 6 x 1 can be used for weapons. Just have them shade in the area as they pick up gear, or put tokens on it, etc. Most characters will have no need for anything beyond this to keep track of their gear, as the remainder of their ENC will be taken up by armor.

  8. I’m horrible at arithmetic, so formulas actually slow the game down more than tables when I’m running.

    This I have some trouble parsing, because operations in D&D are rarely a pure table lookup, there's usually some arithmetic to be done in addition. (For example, combat has ability modifiers, magic weapon and spell bonuses, etc.) So it's hard to see how (1) arithmetic plus (2) table cross-reference could be simpler than just (1) arithmetic.

  9. In the last campaign I ran (B/X) it was almost always pure table look-ups. I almost never had to deal with modifiers for “to hit”, saving throws, morale checks, or anything else. Monsters seldom had modifiers, and the players dealt with any the PCs had.

    (As a player, I usually have as much pre-calculated as possible. One of my last d20 characters must’ve had a dozen lines on its character sheet dedicated to the different kinds of attacks it could make.)

    That said, the amount of arithmetic I have to do in my head does make a difference. Adding three numbers in my head is harder than adding two. 2d6 systems aren’t so bad since I think I’ve finally managed to identify all the combinations on sight. 3d6 systems significantly slow me down.

    The type of arithmetic matters as well. Addition is easier than subtraction or multiplication. Division is harder than the other three.

    And the magnitude of the numbers matters. Adding single digit numbers is much faster for me than double-digit numbers.

    Admittedly, this may be a quirk that only applies to me.

  10. Robert, I think that your comments about the amount, type, and magnitude of numbers in an arithmetic process are indisputable.

    However, from my perspective, big tables of cross-references (or lines of statistics) aggravate me for the amount of space and visual clutter that I need to keep in front of me, taking up table space, while gaming. I know I've gotten more sensitive to this over time (particular since I've been teaching college math for ~8 years now).

    I will point out this: One of the beautiful things about the OD&D AC system is that all AC values are in fact single-digits. So my algorithm of "add the target AC" has been very consciously optimized for both of your last points.