So by now, it’s looking like 5E is going to be my preferred edition of Dungeons & Dragons for the foreseeable future, and it doesn’t look like I’m alone in enjoying it. In fact, perhaps the best sign of 5E’s success is the extent to which it seems to have taken the heat out of the edition wars – even if older versions of D&D will always have their advocates, there really doesn’t seem to be many people who display mortal offence 5E being the official face of D&D; compare this to the 4E era, when in some quarters of the Internet you’d be forgiven for thinking a holy war was taking place.
In particular, 5E seems to have reached an audience of players – and I include myself in this audience – who found the previous Wizards of the Coast versions of D&D not to our liking, presenting a refreshing simplicity and a tone which captures the atmosphere and style of the best of late-period TSR-era D&D whilst providing more rigorous and unified game mechanics and taking the best ideas from 3.X and 4E whilst avoiding the extremes of either of those editions.
This being the case, it’s a good time to take another look at the various TSR-era D&D editions and see whether there’s anything they’re particularly good for, especially if that involves a game experience that 5E either can’t deliver or is less convenient for.
Let’s address the elephant in the room first: yes, the three little brown books of OD&D really don’t explain themselves very clearly at all. Whilst they aren’t completely oblique, even a cursory read-through will find points where, if you are just running these three booklets to run a game, you’re going to need to make a judgement call on just how a particular part of the game works. (For me, the big thing is how elves are supposed to work – on the one hand, they are described as acting as either fighters or magic-users and having to choose which before each adventure, but at the same time they also enjoy the benefits of both classes. Just how you reconcile this – and how to handle their experience progression – is left as an exercise for the reader.)
Then again, Gygax and Arneson shouldn’t be slammed too much for not explaining themselves with perfect clarity. You have to bear in mind what audience the game was written for, rather than the audience it actually found. Textually speaking, it seems obvious to me that Gygax and Arneson were addressing themselves to experienced wargamers of the freewheeling DIY age of the 1960s and 1970s, when cobbling together a bunch of rules and elements from diverse sources and mashing them up on your gaming table to suit the needs of the simulation you were after was par for the course. Referees are advised to look to Chainmail for the full combat system (the familiar target number-vs-descending AC system being presented here as an alternative) and to Outdoor Survival for the wilderness map, and so on. Accounts of Dave Arneson’s Blackmoor campaign (as well as other Twin Cities area games, such as MAR Barker’s Tekumel campaign) suggest that tabletop RPG rules were only one of many tools used in the campaign, with Arneson and Barker’s games shifting almost seamlessly from RPG sessions to handle individual-scale events to various breeds of wargame to settle larger-scale matters, and I rather suspect this closely resembles the sort of thing Gygax expected D&D would be used for – the individual-scale component of a broader fantasy campaign, rather than the single game system governing an entire campaign.
Written as it was as a toolkit for folk who could be expected to know what they were doing and who could also be expected to look to other game systems or homebrew something themselves to settle matters beyond the scope of the rules here, and also burdened with the task of describing an entirely novel gaming format and structure, I think OD&D can be forgiven for being a little obtuse. What’s more, it’s entirely possible to overstate just how oblique it is – yes, you have to fill in the gaps, but the dramatic spread of the game in the 1970s (to the extent that TSR could barely keep up with demand and pirate copies circulated as a result of the shortage) demonstrates that there was an active, imaginative audience out there who were more than happy to fill in those gaps, even if what they filled it with varied radically from table to table.
That, right there, is the unique selling point of OD&D. Everything that has followed it – whether it’s been an official D&D edition or a retroclone, has intrinsically been an exercise in expressing the designers’ particular way of filling in the gaps in OD&D. Some of them might capture the nostalgia of the dungeon-and-wilderness exploration gameplay emphasised by this edition, but none of them quite capture the experience of interpreting the thing for yourself. Sit down and play OD&D, keep a record of your rulings and apply them consistently, and soon enough you and your group will have developed your very own homegrown D&D – indeed, you’ll be well on the way there before you even finish character generation. This is doubly true if you set aside the assumptions you’ve inherited from subsequent editions and let your imagination run wild when coming up with your own interpretation. Some of the OSR people like to refer to their preferred style as “DIY D&D“, and OD&D pretty much offers the epitome of that experience. Level progression runs up to 9-11ish depending on class, so there’s scope for plenty of play to take place whilst at the same time the whole “linear fighter/quadratic wizard” thing, whilst still a thing, doesn’t run as completely out of hand as it does in some editions.
Use This When: You want to yank the DIY dial to 11 and get the authentic mid-1970s experience. Adding on subsequent supplements gets you something increasingly close to AD&D, to the point where unless you’re taking a particularly idiosyncratic selection of options from the supplements rather than the usual bits you might as well just be playing AD&D or B/X or BECMI; trying to play from just the three core booklets and the products of your imagination both requires less work (in terms of deciding what to implement from the supplements) and works better as an exercise in reconstructing how things went down in 1974.
The Holmes-edited Basic Set rulebook is a weird beast, not quite matching up either to Advanced Dungeons & Dragons (which it appears to have been designed as an introduction to, since the text regularly suggests people consult the then-unpublished AD&D rulebooks to cover topics not detailed therein) or to the subsequent B/X and BECMI lines. Its main historical importance is that it’s the first time TSR published an “official” interpretation of OD&D, with the gaps filled in and clearly explained in the text. Granted, some official rulings on rules questions had appeared here and there, but it was Holmes who was tasked with sitting down with the OD&D books and supplements, plus the rules guidance issued, plus Gary’s work on AD&D to date, and come up with a simple introduction to the game that made an easier point of entry for D&D‘s increasingly younger audience than the OD&D booklets.
Since it isn’t quite 100% compatible with any later extension of D&D – neither B/X nor BECMI quite followed its lead, and AD&D went through a number of changes before it finally hit the streets – Holmes has always been the odd one out of the TSR-era D&D lineup. Some of the OSR crowd have tried cooking up extensions of the Holmes game to higher levels – the upcoming Blueholme Complete is intended as a retroclone version of Holmes that extends it to 20th level – but I actually like the idea of a version of D&D that only goes up to 3rd level, and which doesn’t have a developed version of the higher level rules to couple itself to. A D&D campaign where you limit yourself to three levels of play and no more can be nicely short and self-contained; alternatively, a game where you only gain levels through XP up to third and then after that all improvement hinges on getting better gear, uncovering hidden magic, devising better tactics or undergoing unique and secret processes of elevation would be very different from D&D as she is usually played.
Use This When: You want a basic D&D game where things work a little differently from the way many those who cut their teeth on later editions remember, where player characters are always vulnerable and where the linear fighter/quadratic wizard thing never kicks in.
By 1981, Advanced Dungeons & Dragons was out of the door and TSR noted a curious phenomenon – namely, that their audience demographic was broadening. Whereas for much of the 1970s people tended to get into D&D and other such tabletop games when they were around college age and maybe a bit younger – and the AD&D books were written with such an audience in mind – suddenly the zeitgeist had shifted and they discovered that a younger generation was expressing an interest in the game, perhaps helped by the Holmes version of the Basic Set. Holmes Basic, however, had a very major problem by this point – it had never been compatible with OD&D, and it wasn’t quite compatible with the final form of AD&D either – and neither the OD&D booklets nor the AD&D tomes were really written in a style that a 12 year old could easily follow.
Not only was a new Basic Set needed, then, but it would also need to be the gateway drug to a new Dungeons & Dragons – a version of the rules set that combined the clarity of writing that Holmes had demonstrated could be accomplished with sufficient meat on the bones to be a fully-functioning and satisfying RPG. It fell to Tom Moldvay to produce the new Basic Set and David “Zeb” Cook and Steve Marsh to produce the Expert Set, which together cover a level progression from 1-14.
Although people refer to this version of the game as B/X, references in the Expert Set make it clear that a progression to additional sets – which would see the light of day later as the BECMI range – was always envisaged. That said, these two books constitute a complete game in themselves – in fact, between the dungeoneering focus of Basic and Expert‘s coverage of wilderness adventures, building castles and establishing domains, B/X actually covers pretty much the exact same ground as OD&D‘s core booklets whilst adding in the thief from the Greyhawk supplement.
Indeed, like both Holmes Basic and AD&D before it, B/X is effectively an exegesis of OD&D, with its ambiguities and gaps filled in and explained clearly. Unlike AD&D, however, the team of Moldvay, Cook and Marsh don’t try to incorporate everything that was on offer in the OD&D supplement line, instead mostly sticking to the core of the game – and giving themselves the freedom to occasionally come up with different answers to Gary’s when handling ambiguous area of the rules, when doing so will simplify matters. This is most evident in their treatment of nonhuman PCs, in which “elf”, “dwarf” and “halfling” are treated as character classes in their own right rather than separating race and class. This isn’t quite how it’s handled in OD&D, but since the core OD&D books didn’t give any alternative class options for elves, dwarves and halflings the end result is much the same, without the added complexity of separating out race and class.
One major strength of B/X is its eminently sensible refereeing advice – including a down-to-earth suggestion that if you don’t know how to adjudicate something you can just assign an odds-out-of-six chance to it and let the player roll – coupled with its economy of rules. Those rules it does present, it presents clearly and with more or less all of the gaps in the OD&D rules filled in. At the same time, it doesn’t follow the lead of AD&D in offering fiddly little rules to deal with finer points of the simulation or to handle unusual cases, and as such it’s a very bare-bones framework for a game. I suspect that this is why a lot of the modern wave of OSR games, particularly the more divergent ones rather than deliberate retroclones, end up riffing on either OD&D or the various Basic versions of D&D, as opposed to 1E AD&D; if you aren’t working in lots of precise little rules for edge cases and special exceptions you’re not really capturing the spirit of 1E, whereas it’s much easier to take the massively simpler frameworks of OD&D or the Basic versions and adapt them to different purposes.
Use This When: You want to recapture the classic, nostalgic D&D style with a system that gives plenty of scope for houseruling and adaptation and covers everything OD&D offers whilst not having as many gaps to fill in as OD&D.
I have to confess to a smidge of bias here; the Rules Cyclopedia is the first RPG product I ever owned, so the odds of me slamming it are remote in the extreme simply thanks to the sentimental value.
Nonetheless, I think it remains the best statement of the BECMI line of the game. It doesn’t include the “I” part, beyond rules for ascension to immortality – the Immortals rules being revised and presented in the separate Wrath of the Immortals boxed set – but the Immortals game was effectively a whole distinct game from the rest of BECMI, with Immortal characters effectively being designed on a whole different basis and scale in order to account for their supreme power and the cosmic scale of their adventures. Since only the most long-running campaigns could ever expect to see a single PC ascend to immortality through playing from level 1 in the first place, its absence hardly cramps anyone’s style, and indeed I suspect most Immortals games were played by folk who specifically planned from the get-go to play an Immortals game.
The Rules Cyclopedia, then, consists of Aaron Allston taking the BECM boxes and a pinch of I and integrating them into a cohesive whole. The BECMI boxed sets – Basic, Expert, Companion, Master and Immortal – were designed by Frank Mentzer from 1983 to 1985. The latter three sets were original to this edition, and as well as the aforementioned divine ascension and immortals rules included detailed rules for mass battles, domain management, and a range of optional bits and pieces derived from the broader OD&D range; the Basic and Expert sets were complete revisions of the Moldvay-Cook-Marsh sets with an emphasis on tweaking the math to better fit a progression to 36th level and an even younger reading age.
The thing about BECMI is that by the time you have five boxed sets of stuff, including bits in later boxes that add new options suitable for the level tiers of earlier boxes, it’s downright unwieldy to juggle that many books. At the same time, if you just limit yourself to the first couple of boxes or something then you may as well just play B/X, especially since BECMI does rather screw over some character types if you don’t allow options from the later sets. (In particular, thieves get boned at low level in BECMI on their skill percentages due to the need to stretch their skill advancement out over 36 levels.)
The Rules Cyclopedia doesn’t distinguish between which rule goes in which set, but integrates them into a seamless whole and clearly flags which rules are optional, in a presentation very reminiscent of Zeb Cook’s work on AD&D 2E. What you get out of that is a system clearly distinguished from AD&D by decisions like race-as-class and paladins as a sort of early prestige class that high level fighters could qualify for and other such distinctions, and also offers far superior support for domain management, mass battles and sieges than any other edition of the game has ever offered, whilst at the same time being simple enough to encapsulate in one book.
On top of all that, the Cyclopedia also throws in an introduction to Mystara, the BECMI campaign setting developed through modules and the Gazetteer series of setting supplements and which would see subsequent development in the Poor Wizard’s Almanac series. Whilst Mystara doesn’t often make sense by Earthly logic, it is a campaign world built from the ground up to reflect the distinctive BECMI rules, and the setting material here offers plenty of seeds for further development. Guidelines for conversion to and from AD&D 2E are given, but whilst some Mystara products were made for AD&D after the basic line was retired for good it’s a better fit for BECMI, the setting that shaped its cosmos in the first place.
Use This When: You want a D&D that covers lots of options in a single book, or when you want to run a game with a significant domain management or mass battle aspect, or if you fancy exploring Mystara.
It’s become a well-aired fact by this point that the intention behind Advanced Dungeons & Dragons was to provide a coherent, consistent set of rules for the purposes of tournaments and other types of organised play, as well as to improve consistency of experience and dial back the wild degree of local variation in interpretation of D&D that characterised the OD&D era (and to hopefully ease off on the number of rules queries pouring into TSR!). This is no great insight; Gary Gygax makes this point explicit from the get-go. What it also provides, as part of that, is a heaped spoonful of insight into why TSR-era D&D is the way it is.
One of the things a lot of people come away from when they read these core books – especially the Player’s Handbook and Dungeon Master’s Guide, which are much less straight-down-to-business than the Monster Manual – is how intensely waffley they are, with Gygax offering mini-essays on all sorts of topics. (He begins the Dungeon Master’s Guide by offering the reader an honest to goodness mini-lecture on die roll probabilities.) Some quarters of the OSR love this “Gygaxian prose” for its own sake, almost to a point of fetishising it, but I think there is an extent to which it is a double-edged sword. On the one hand, it can have the unfortunate consequence of obscuring some rules and cluttering up the presentation of the rulebooks, which could be much clearer. (Indeed, 2E would accomplish a much more easily understood presentation of AD&D and 90% of that involves rewriting the whole text to much better communicate the rules concepts.) On the other hand, it’s also immensely valuable as an explanation of why various parts of the game are the way they are – for instance, there’s a section in the Dungeon Master’s Guide which explains how demihuman level limits are applied because the game is conceived of specifically as being a humanocentric game.
This is a boon to anyone who wants to understand the design of the game, and is especially useful to anyone who wants to actually houserule TSR-era D&D, because it helps to flag what effect a particular rule is intended to accomplish, allowing you to both judge whether you’re applying it right, whether the rule actually is having the effect it’s supposed to have at your own table, and what unexpected consequences might arise from changing it. The player advice in the Player’s Handbook is invaluable for setting expectations if you’re going to be playing in a consciously “old-school”-styled game; likewise, the refereeing advice in the Dungeon Master’s Guide is extremely useful if you want to run the game as Gary envisaged it, and if you don’t want to do that it’s still useful in working out what you need to change to make the game work the way you want it to.
In this respect, I think Gary managed to pull off a very sly trick, though there is ample room for debate as to whether or not it was intentional. On the one hand, these books provide a useful amalgamation of OD&D and supplements which largely sets aside the need to puzzle out just how some of the moving parts are meant to fit together, and provides a clear model for the sort of standardised gaming the AD&D project was supposed to promote. At the same time, Gygax’s tangents provide the reader with a deep enough understanding of the system to go decidedly non-standard if they have the desire to do so. In other words, it’s not so much like learning how a car engine works by reading the manual yourself and more like an avuncular engineer opening up the bonnet for you, taking you through the different parts of the engine, and explaining what each part does and why it’s designed that way.
Of the three books, the Monster Manual is a particularly useful one for any incarnation of TSR D&D, since aside from mild conversions needed (such as the differing armour class scale between OD&D and the various Basic incarnations on one hand and the Advanced line on the other) the monsters can be happily dragged-and-dropped into any other version of TSR D&D without trouble. (Indeed, you don’t necessarily have to bother with the conversions – the AC adjustments will only make a difference of one point either way, after all, which does have some small effect but is “close enough for government work” in my eyes.) It’s even useful if you have 2nd Edition, since it details the various devils and demons with many more options than the tiny selection offered in the Monstrous Manual. It also provides a nicely sparse baseline for monster descriptions, so it can be handy to use if you want to deploy these monsters but come up with your own interpretation of them based on the central premise offered here rather than following the more expansive treatments they get in the monster books of later editions.
On the other hand, the Player’s Handbook adequately covers character generation, equipment purchasing and spell selection, and it provides a reasonable set of rules for half-orcs (for those who want to, for instance, use those in 2E without resorting to The Complete Book of Humanoids) and assassins (which to my eye look better than the assassin thief kit from The Complete Book of Thieves in 2E), it is missing some significant features. For instance, the combat matrices and other significant tables and details are all in the Dungeon Master’s Guide, leaving players mostly reliant on the Dungeon Master to tell them when they have or haven’t hit. Now, to be fair this is entirely consistent with Gygax’s reported refereeing style, in which largely players weren’t expect to engage too much with the fine details of the rules in favour of declaring their intentions and rolling dice as directed, and if you want to run a game in that style it’s just fine. On the other hand, if you want to run a game in that style you can still do it whilst giving the players a full overview of the combat system by simply not telling them what the armour class of the enemies they are facing is, whereas if you want to run a game where the players have a fairly good idea of what the rules are and are able to shoulder part of the burden of working out whether they’ve succeeded or not then the Player’s Handbook by itself doesn’t quite give you those tools.
Speaking of tools though, the Dungeon Master’s Guide for this edition is a true masterpiece, offering not just an in-depth discussion of the system but also an incredibly deep grab-bag of information, random tables, and other guidance for subjects ranging from stronghold construction to filling out city encounters to generating dungeons and more besides. It also provides the best overview of artifacts you can find in the TSR D&D range outside of 2E‘s separate Book of Artifacts, and in general manages to cram in more material in its pages than any subsequent Dungeon Master’s Guide, making it a useful resource to keep on hand to dip into even for post-TSR versions of D&D. (The random prostitute table might be a step too far for most games, mind.)
And really, one of the things this version of the game is best for is dipping into. Whilst some old schoolers out there take pride in playing and running 1E as-written, many others confess that they never actually did that – instead, they just used it as a source of monsters, items, spells, and character creation details and used rules procedures inherited from OD&D or Basic. To be honest, there’s a lot of material in here which even Gary himself admitted he never used in his own games but included for a sense of completeness – the optional psionic rules are a major example there – and still more stuff which few people have the patience to use in practice (such as adjustments for weapon speed and weapons vs. armour types).
Use This When: You want to really get under the hood of TSR-era D&D and see how it works, or you want to have an especially deep and varied toolkit of resources to draw on.
“Zeb” Cook didn’t re-invent the wheel with the 2E core books, but then again that was never the purpose. Whilst the total re-organisation and rewriting of the rules could be interpreted as a cynical bid to deny royalties to Gary Gygax, it was also unquestionably needed, particularly with the shift that had already begun with people diving in straight to AD&D as a starter game rather than the BECMI line, which TSR had just begun to neglect at around this time and ended up walking away from entirely midway through 2E’s tenure.
The major gear shift between this and 1E is TSR stepping away a little from standardisation. Whilst organised play and tournaments are still a consideration – there’s even an advert for the RPGA at the back of my copy of the Player’s Handbook – a wide swathe of rules in both the Player’s Handbook and the Dungeon Master’s Guide are tagged as being optional. In some cases, multiple different options are presented – for instance, when it comes to skills going beyond your immediately obvious class powers, you can go the old-school route of rolling up a secondary career and having your character be broadly good at the sort of stuff members of that profession would be good at, or you could use the non-weapon proficiency rules (a cleaned-up version of the rules which had crept in in the late 1E era), or you can not bother at all and just wing it.
The Player’s Handbook also brings in the split of spells into wizardly schools and priest spheres, as was previewed in the Dragonlance Adventures hardcover, allowing for the portrayal of a range of specialist wizards straight out of the book and pointing to how speciality priests could be implemented. Indeed, a major part of the 2E project seems to have involved adding extra flavour to the character classes, though a large part of this would be through the use of class kits in the Complete (Whatever)’s Handbook series of splatbooks. I intend to look at those in a later article, but my major thought about the kit mechanic is that it’s a clunky solution to a problem that 5E solves much more elegantly with its Backgrounds mechanic, but if you want to implement the 2E versions of kits then you really need to be running 2E to do it, since a lot of their differentiation arises from the nonweapon proficiency rules presented here.
Another thing the 2E Player’s Handbook does is provide a far larger proportion of the system than the 1E book did – 2E players are equipped to understand what is going on in combat far better, in particular. This makes sense partly as a reflection of shifting priorities in gaming, partly because the old 1E combat system just wasn’t a mystery any more – keeping secrets is all very well, but there’s a statute of limitations on these things.
Unfortunately, the shift of material to the Player’s Handbook from the Dungeon Master’s Guide, whilst it does mean much less cross-referencing when you want to figure out how a bit of the rules works, isn’t accompanied by a commensurate increase in fresh, new material on offer in the Dungeon Master’s Guide. In fact, the 2E Guide is downright sparse, offering useful advice on implementing the system and a few things like treasure and magic item descriptions and rules for awarding experience points and class design that are of use, but presenting nowhere near the encyclopedic range of tools and useful bits that the 1E Guide did. Whilst subsequent supplements would meet the gap to a certain extent, I’d still suggest anyone looking to run a 2E campaign to have a copy of Gary’s original 1E Dungeon Master’s Guide to hand simply because of all the useful stuff in there which isn’t replicated here. There are those who consider the 2E Dungeon Master’s Guide to be the worst Guide of any edition, and I can’t really disagree there – it’s not that the material here is bad, far from it, it’s just that there really isn’t that much of it.
The monster book for 2E went through a couple of incarnations. Initially, TSR tried to push the Monstrous Compendium on us – a big fat ring binder of monsters, with specialised appendixes (like compendia for specific campaign settings) sold as bundles of extra sheets to go in the binders. This was a fun idea that rapidly became irritating when it came to its logistical implementation and was scrapped in favour of more conventional monster books, with the new Monstrous Manual being the core one.
That said, a happy side-effect of the ring binder format was that each monster needed to fill an entire sheet of the book (unless several closely-related monsters could viably share a sheet). The way the writers padded the material out was to provide discussions of the ecology, habitat, and – for those monsters that exhibited it – social behaviour of the monsters in question. This is an absolute boon for world builders. Whilst the 5E Monster Manual is very, very good at giving you enough detail on a monster to have a solid idea of how to deploy it in an adventure, the 2E Monstrous Manual shows you how a monster fits into a world, and so referees very keen on constructing vivid settings with a sense of verisimilitude could do a lot worse than use the 2E Monstrous Manual as an aid in this.
So, a solid Player’s Handbook, a weak Dungeon Master’s Guide, a monster book which is pretty damn good but took a couple of tries before it found a useful format, and a rules system that resembles 1E with all the bits people couldn’t be bothered with brushed under the carpet: all very well, but what’s the unique selling point of 2E? Many would say the campaign settings. Whilst some settings have seen the light of day in subsequent editions – Greyhawk, Forgotten Realms, Dragonlance, Ravenloft and Dark Sun all got at least some love after 2E – in many cases fans consider the 2E renditions of those campaign settings to be the definitive and best versions thereof. (Even in the case of Greyhawk, whose heyday was arguably the 1E era, there’s a faction of fans who consider the 2E era From the Ashes boxed set to be their favourite presentation of the setting.) Still more settings never saw the light of day after 2E – Planescape, Birthright, and Spelljammer were 2E exclusives, whilst Mystara – previously the setting developed in the BECMI Gazeteer series – had a late renaissance under 2E, especially when it came to the 2E-exclusive Red Steel campaign setting.
Whilst it is entirely possible that 5E versions of all these settings will eventually see the light of day, odds are that some of the less well-celebrated settings will remain as legacy products generating a trickle of PDF sales on dndclassics.com, and given the sluggish pace of Wizards’ 5E publication schedule it seems doubtful that even flagship campaign settings like the Forgotten Realms will get as broad and deep a range of products for them under 5E as they received under 2E. Whilst conversion from 2E to 5E is far from difficult, it can still be useful to have the 2E books on hand to perform such conversions – and if you just run the settings in question in 2E, you save yourself the job of conversion altogether.
Use This When: You want to play a version of AD&D which is much easier to navigate than 1E, or if kits and/or proficiencies really appeal to you, or when you want to use one of those classic campaign settings.
And What of the Clones?
Retro-clone RPGs arose for two reasons. The first and more obvious one is to use the D20 OGL to craft games which allow people to play old editions of Dungeons & Dragons without scoring second-hand copies of the books. The second reason, and the primary impetus behind the completion of OSRIC (the primary 1E retro-clone and the first game to kick off the flood of them), is to provide a way for people to publish support materials for old versions of Dungeons & Dragons – say that your product is “compatible with (retro-clone)”, and customers in the know will be able to tell that it’s also compatible with the appropriate edition of D&D.
The first purpose is basically redundant, for the time being – Wizards of the Coast seem to have decided that, in retrospect, pulling all the D&D PDFs from DriveThruRPG was a daft idea, and dndclassics.com seems to have been a reasonable success for them. Although in principle they could pull the PDFs all over again, in practice this would be utterly pointless – they know full well that all this would accomplish would be to drive customers to the retro-clones, so in a situation where they can’t stop people putting out PDFs of their old rules (or simulacra close enough as to make no difference) they might as well sell the PDFs themselves and get some scratch out of it. Of course, the OD&D booklets aren’t on dndclassics yet, so I suppose until that is the case there’s still a space for Swords & Wizardry, and even once those PDFs are out Swords & Wizardry may have a place in the ecosystem since it’s much better organised than the OD&D booklets and does a lot of the heavy lifting of interpreting them for you – but as I’ve argued above, doing an exegesis of OD&D is part of the point with engaging with OD&D in the first place, and B/X already provides a perfectly good interpretation of OD&D – whilst it does differ from OD&D in some respects, these are so slight that only people who get really intensely nit-picky about very minor details of the rules could possibly consider that a deal-breaker.
For the most part, then, the purist retro-clones are semi-redundant: they’re still useful as tags to put on a product if you fancy churning out products for TSR-era D&D, but actually using their core rulebooks isn’t actually that much more convenient than using the actual editions they’re mimicing, particularly since aside from OD&D most TSR versions of D&D are available for decent prices second-hand if you really want hardcopies of stuff. This is presumably why the OSR scene is moving away from straight clones; Lamentations of the Flame Princess‘s successive releases put increasing emphasis on its particular aesthetic and the conceit of setting the game in 16th Century Europe, for instance, whilst Sine Nomine’s Scarlet Heroes is interesting more in the way it tweaks TSR-era D&D to better support games with only 1 player character than in its emulation of any particular edition of TSR-era D&D.
In general, I find that I’m more interested in D&D-alike OSR games the further they drift from traditional D&D fantasy. Adventurer Conqueror King System might have an interesting domain management system attached, but I don’t really fancy investing in yet another presentation of B/X basic principles just to get my hands on those domain rules. Conversely, I very much see the point of a game like Stars Without Number, which adapts old-school D&D to support a game much like old-school Traveller. It’s not for me – I already have a game which covers that type of play perfectly well, it’s called Traveller – but it feels like a more worthwhile idea for a project than yet another restatement of old-school D&D.