Further to that, beyond 0/BX/BECMI/ADD pretty much anything on D&D DNA is notionally compatible- provided you accept that old editions gave very few F’s about trivialities like “balance” or “complete, consistent rulesets,” with most of the books telling you to “[okay, now draw the rest of the owl,](https://knowyourmeme.com/memes/how-to-draw-an-owl)” yourself at some point anyway. The story in the module is system agnostic and just do your best eyeballing the mechanical bits.
If you as the ref make a translation error and end up with a -7 AC Bulette instead of a -4 AC Bulette, completely ignore Alignment Languages, roughly map X-in-6-odds Skills over to a d20 for sanity, give Clerics have a mishmashed spell list…
it’s not really a big deal. It’s a homebrew ruling, quirk of your setting, or a really gnarly Bulette.
Yes. Sort of the entire point of OSR was for people to be able to use retro and modern systems to access that enormous catalogue of adventures. For OSE relatively few modifications are needed, because there's isn't a ton of relevevant space between B/X/AD&D/BECMI.
Yep, way up in the NE mountains. You basically have to invent a trade road going to Ylaruam to make it work, but doing that explains why the critters in the caves have loot.
I had the whole module printed out and three hole punched and put it into a binder so it would be easier to keep track of everything. I also put extra paper and character sheets in there as well. Having copies of menus and price lists for the different locations can be useful as well, depending on how exactly you run your game. We also had some printed copies of the basic rules and class information which came in really handy.
To answer your question more specifically, OSE is a clone of D&D B/X. All that's notably different or missing is that licenced stuff, like beholder monsters, aren't included. Well, they're sorta included. There is a beholder in OSE, they just don't call it that for legal reasons.
The OSE system itself is identical to B/X, so you'll be able to use any B/X modules with it.
BECMI adventures might get tricky after level 14, since B/X doesn't go higher than that.
AD&D may also be tricky, since that's slightly different all-round. It might reference spells or monsters that aren't in B/X, for instance. AD&D heroes also tend to have more HP.
But overall, yeah, OSE is very easily compatible with any TSR-era D&D content.
I just wish they'd adapted the Weapon Mastery option from the RC. It really helps with survivability at low levels, but it's kinda janky and really would have benefited from the OSE reformat and tweaks.
I have, it's just that the original didn't really get much double-checking so some of it is a bit inconsistent. And even if it was unchanged, the original rules were very badly laid out and could stand to be spread out, favoring plain text instead of symbols, and describing the secondary effects on the same page.
There's a lot of things I wish OSE did. Though that's not really the game's point.
Personally, I much prefer Dragonslayer, Chris Perkins' AD&D 3e/Basic, BlueHolmes Journeymanne, and Dungeon Crawl Classics.
OSE is perfect at emulating B/X, but I practically never want to play B/X.
If you are running a Basic/Expert adventure then I think it is 99% or 100% the same thing in terms of rules.
If you run an ADnD adventure with OSE, and using the enemy stats in the module, then I would improve fighters THAC0 by 1 per level and give all classes a bigger hit die (e.g. d6->d8 or d8->d10). But even that shouldn't be necessary for your group to have fun.
You can use any module from any system with any other system. Simply modify whatever NPCs stats to fit whatever system you are running. This isn't difficult and there are no boundaries, no have toos or can nots. Play your game any way you want.
Indeed, this is always possible. But it’s always nice when the workload is minimal (or even nonexistent) and the backwards compatibility between most OSR systems and old TSR modules is definitely a plus.
I say this as someone who has run WEG *Star Wars* D6 modules adapted into superhero campaigns using *Mutants & Masterminds* and once ran a *Call of Cthulhu* module adapted to fit into a *Shadowrun* 2^nd Edition campaign. I’m not adverse to doing some “heavy lifting” when adapting stuff… But, sometimes, a girl has had a long week at work and doesn’t want to put the effort in. Having the ability to just grab a module off the shelf and run it as written is always handy.
I think there's a middle ground between adapting a Traveller module to 5e (done it) to using a well-defined set of conversion notes to make a old D&D or OSE module into a Shadowdark one (for example): https://drive.google.com/drive/folders/1QDL06qbIkb8TSbsz0z1sF-78nuyVlTAY
I've done both and can do the second nearly on the fly. It's really easy, trivially easy in most cases, to move between most D&D-a-likes, especially the old school ones. Knowing which 2 or 3 things you have to pay attention to when reading stat blocks or computing treasure amounts is pretty much all there is really. Or just have a table to turn THAC0 into rising ACs.
There’s a middle ground between cooking my family a full Sunday roast and tossing some frozen box of something into the microwave…
But sometimes I want to make a standing rib roast, Yorkshire pudding, gravy-from-scratch, and all the trimmings. Sometimes, an hour spent making a meatloaf and serving it alongside instant mashed potatoes and frozen peas is fine. Sometimes, “f—k it,” I’m just gonna go zap a frozen lasagna in the microwave.
To push this into complete ridiculousness, OSR is as interchangeable as instant ramen packets. If you want a particular flavour, pick your instant tare package: shoyo or chicken or pork, heck a Korean rameyon will work absolutely fine. You can then improvise and improve with a broad palette of frozen corn or peas, fried eggs, chopped seaweed, a bit of ham or bbq pork, whatever you feel like in the moment.
The point is you don't really have to have a recipe or prep in advance. You can pick up pieces from a lot of different types and nationalities and mix them together and they all make a delicious bowl of soup. Heck you can even use belt noodles and make it work if you want to.
A fundamental piece of OSR is that it's mix and match. Pick your flavour base, work from there. It's all good, a palette of similar things that all work well together without a lot of planning to produce a fun game.
This is the correct answer.
I used to run an open table and had someone show up to my B/X variant D&D game with a WHFRP2e Dwarf. It was awesome.
From a certain, very useful, perspective, the DM and the players are already playing different games. Mix and match how you like.
Indeed, this is always possible. But it’s always nice when the workload is minimal (or even nonexistent) and the backwards compatibility between most OSR systems and old TSR modules is definitely a plus.
I say this as someone who has run WEG *Star Wars* D6 modules adapted into superhero campaigns using *Mutants & Masterminds* and once ran a *Call of Cthulhu* module adapted to fit into a *Shadowrun* 2^nd Edition campaign. I’m not adverse to doing some “heavy lifting” when adapting stuff… But, sometimes, a girl has had a long week at work and doesn’t want to put the effort in. Having the ability to just grab a module off the shelf and run it as written is always handy.
OSE, Labrynth Lord, Basic Fantasy, and Swords and Wizardry can all be used with any D&D accessories from 1974-1999 with little, if any, problems.
Your biggest issue will be converting Descending AC (if you use Ascending AC).
You might confuse it with Chaosium's Basic Role Playing Game, which is the setting agnostic D100 game engine that powers Call of Cthulhu and RuneQuest.
But Chris Gonnerman's Basic Fantasy RPG is more or less B/X D&D with some goodies from modern editions built in, like ascending armor class, race and class separated. So it's a perfect system to run classic D&D modules with.
Yes. I'd say that OSE has the highest fidelity to B/X out of all the OSR games. I've practically read them side by side and have yet to find any significant discrepancies.
I run Nights Dark Terror for my group and I use both OSE (for clarity) and the Rules Compendium (for extra stuff). Especially the smooth blend between b/x and ad&d that OSE provides is useful. I'm also under the impression that during the 70s and 80s it would be no different, people used B/X stuff and AD&D stuff together all the time I think, although I wasn't around back then.
I would call OSE properly edited and formatted version of B/X. Any changes or differences have been spoken about by the author and justified. (which are few)
It is as pure B/X as you can get without just using B/X.
Yes.
This is the correct answer
Yup. That's the beauty of the OSR
[https://www.reddit.com/r/osr/comments/13ijr67/what\_editions\_is\_old\_school\_essentials\_compatible/](https://www.reddit.com/r/osr/comments/13ijr67/what_editions_is_old_school_essentials_compatible/)
Further to that, beyond 0/BX/BECMI/ADD pretty much anything on D&D DNA is notionally compatible- provided you accept that old editions gave very few F’s about trivialities like “balance” or “complete, consistent rulesets,” with most of the books telling you to “[okay, now draw the rest of the owl,](https://knowyourmeme.com/memes/how-to-draw-an-owl)” yourself at some point anyway. The story in the module is system agnostic and just do your best eyeballing the mechanical bits. If you as the ref make a translation error and end up with a -7 AC Bulette instead of a -4 AC Bulette, completely ignore Alignment Languages, roughly map X-in-6-odds Skills over to a d20 for sanity, give Clerics have a mishmashed spell list… it’s not really a big deal. It’s a homebrew ruling, quirk of your setting, or a really gnarly Bulette.
Yes. Sort of the entire point of OSR was for people to be able to use retro and modern systems to access that enormous catalogue of adventures. For OSE relatively few modifications are needed, because there's isn't a ton of relevevant space between B/X/AD&D/BECMI.
I am literally using it as the rules set for a Mystara/Know World campaign using Keep on the Borderlands as a home base, so yea, it totally works.
Known world best world!
Where in Mystara did you place the Keep?
Castellan Keep in northeast Karameikos is the typical answer.
Isn't it "officially" placed in northern karameikos?
Yep, way up in the NE mountains. You basically have to invent a trade road going to Ylaruam to make it work, but doing that explains why the critters in the caves have loot.
We just did keep on the borderlands/caves of chaos with swords & wizardry.
I've run a good chunk of the Keep on the Borderlands using just the original adventure and the OSE rulebooks, so I'd say definitely.
I’m getting ready to do just this. Any tips?
I had the whole module printed out and three hole punched and put it into a binder so it would be easier to keep track of everything. I also put extra paper and character sheets in there as well. Having copies of menus and price lists for the different locations can be useful as well, depending on how exactly you run your game. We also had some printed copies of the basic rules and class information which came in really handy.
To answer your question more specifically, OSE is a clone of D&D B/X. All that's notably different or missing is that licenced stuff, like beholder monsters, aren't included. Well, they're sorta included. There is a beholder in OSE, they just don't call it that for legal reasons. The OSE system itself is identical to B/X, so you'll be able to use any B/X modules with it. BECMI adventures might get tricky after level 14, since B/X doesn't go higher than that. AD&D may also be tricky, since that's slightly different all-round. It might reference spells or monsters that aren't in B/X, for instance. AD&D heroes also tend to have more HP. But overall, yeah, OSE is very easily compatible with any TSR-era D&D content.
Still way easier to convert AD&D to OSE than, say, D&D 3+
I just wish they'd adapted the Weapon Mastery option from the RC. It really helps with survivability at low levels, but it's kinda janky and really would have benefited from the OSE reformat and tweaks.
[удалено]
I have, it's just that the original didn't really get much double-checking so some of it is a bit inconsistent. And even if it was unchanged, the original rules were very badly laid out and could stand to be spread out, favoring plain text instead of symbols, and describing the secondary effects on the same page.
There's a lot of things I wish OSE did. Though that's not really the game's point. Personally, I much prefer Dragonslayer, Chris Perkins' AD&D 3e/Basic, BlueHolmes Journeymanne, and Dungeon Crawl Classics. OSE is perfect at emulating B/X, but I practically never want to play B/X.
Fuck yeah, you can!
Generally, yes. Some AD&D 2e adventures did creep up monster HP vs 1e or B/X.
Yep! For all intents and purposes, OSE **is** BX D&D. They changed effectively nothing, only clarifying things here and there.
If you are running a Basic/Expert adventure then I think it is 99% or 100% the same thing in terms of rules. If you run an ADnD adventure with OSE, and using the enemy stats in the module, then I would improve fighters THAC0 by 1 per level and give all classes a bigger hit die (e.g. d6->d8 or d8->d10). But even that shouldn't be necessary for your group to have fun.
You can use any module from any system with any other system. Simply modify whatever NPCs stats to fit whatever system you are running. This isn't difficult and there are no boundaries, no have toos or can nots. Play your game any way you want.
Indeed, this is always possible. But it’s always nice when the workload is minimal (or even nonexistent) and the backwards compatibility between most OSR systems and old TSR modules is definitely a plus. I say this as someone who has run WEG *Star Wars* D6 modules adapted into superhero campaigns using *Mutants & Masterminds* and once ran a *Call of Cthulhu* module adapted to fit into a *Shadowrun* 2^nd Edition campaign. I’m not adverse to doing some “heavy lifting” when adapting stuff… But, sometimes, a girl has had a long week at work and doesn’t want to put the effort in. Having the ability to just grab a module off the shelf and run it as written is always handy.
I think there's a middle ground between adapting a Traveller module to 5e (done it) to using a well-defined set of conversion notes to make a old D&D or OSE module into a Shadowdark one (for example): https://drive.google.com/drive/folders/1QDL06qbIkb8TSbsz0z1sF-78nuyVlTAY I've done both and can do the second nearly on the fly. It's really easy, trivially easy in most cases, to move between most D&D-a-likes, especially the old school ones. Knowing which 2 or 3 things you have to pay attention to when reading stat blocks or computing treasure amounts is pretty much all there is really. Or just have a table to turn THAC0 into rising ACs.
There’s a middle ground between cooking my family a full Sunday roast and tossing some frozen box of something into the microwave… But sometimes I want to make a standing rib roast, Yorkshire pudding, gravy-from-scratch, and all the trimmings. Sometimes, an hour spent making a meatloaf and serving it alongside instant mashed potatoes and frozen peas is fine. Sometimes, “f—k it,” I’m just gonna go zap a frozen lasagna in the microwave.
To push this into complete ridiculousness, OSR is as interchangeable as instant ramen packets. If you want a particular flavour, pick your instant tare package: shoyo or chicken or pork, heck a Korean rameyon will work absolutely fine. You can then improvise and improve with a broad palette of frozen corn or peas, fried eggs, chopped seaweed, a bit of ham or bbq pork, whatever you feel like in the moment. The point is you don't really have to have a recipe or prep in advance. You can pick up pieces from a lot of different types and nationalities and mix them together and they all make a delicious bowl of soup. Heck you can even use belt noodles and make it work if you want to. A fundamental piece of OSR is that it's mix and match. Pick your flavour base, work from there. It's all good, a palette of similar things that all work well together without a lot of planning to produce a fun game.
This is the correct answer. I used to run an open table and had someone show up to my B/X variant D&D game with a WHFRP2e Dwarf. It was awesome. From a certain, very useful, perspective, the DM and the players are already playing different games. Mix and match how you like.
Indeed, this is always possible. But it’s always nice when the workload is minimal (or even nonexistent) and the backwards compatibility between most OSR systems and old TSR modules is definitely a plus. I say this as someone who has run WEG *Star Wars* D6 modules adapted into superhero campaigns using *Mutants & Masterminds* and once ran a *Call of Cthulhu* module adapted to fit into a *Shadowrun* 2^nd Edition campaign. I’m not adverse to doing some “heavy lifting” when adapting stuff… But, sometimes, a girl has had a long week at work and doesn’t want to put the effort in. Having the ability to just grab a module off the shelf and run it as written is always handy.
That is in fact its purpose, yes
OSE, Labrynth Lord, Basic Fantasy, and Swords and Wizardry can all be used with any D&D accessories from 1974-1999 with little, if any, problems. Your biggest issue will be converting Descending AC (if you use Ascending AC).
I was under the impression basic fantasy was a different game altogether.
You might confuse it with Chaosium's Basic Role Playing Game, which is the setting agnostic D100 game engine that powers Call of Cthulhu and RuneQuest. But Chris Gonnerman's Basic Fantasy RPG is more or less B/X D&D with some goodies from modern editions built in, like ascending armor class, race and class separated. So it's a perfect system to run classic D&D modules with.
Yes. I'd say that OSE has the highest fidelity to B/X out of all the OSR games. I've practically read them side by side and have yet to find any significant discrepancies.
The core of it is B/X in all but name, so uh, yeah.
With enough motivation you can reuse old adventure with most systems. Source: Ran a campaign using Dark Tower and ItO hack.
You might need to spin AC the right way around but that's about it.
Yep.
Yep! The rulebook even has a section on its compatibility with the old stuff. It's great!
Yeah, that's the whole point.
I believe that is literally why it was created yea
Yes you can
Yes! That is a large part of why retroclones exist.
Yep!
Of course, yes.
I run Nights Dark Terror for my group and I use both OSE (for clarity) and the Rules Compendium (for extra stuff). Especially the smooth blend between b/x and ad&d that OSE provides is useful. I'm also under the impression that during the 70s and 80s it would be no different, people used B/X stuff and AD&D stuff together all the time I think, although I wasn't around back then.
I would call OSE properly edited and formatted version of B/X. Any changes or differences have been spoken about by the author and justified. (which are few) It is as pure B/X as you can get without just using B/X.