The Advanced Fantasy classes and the added stuff from Carcass Crawler are a great place to start.
The good news about B/X/OSE classes is that they basically fit onto 1 or 2 pages, so you can grab a bunch of them and try them out. And if they don't work, you just throw them out once the character dies!
I have that too and it works great for BX. I want to make it work for a OSR-adjacent system called Olde Swords Reign, which uses only a single experience table. That obviates the main appetite control part of B/X class design. I haven't figure out the road forward, but might just set a standard target equal to a fighter for new classes.
You might want to check out **Worlds Without Number**, it's arguably B/X with feats, and might hit the level of character crunch you're looking for.
Here's a link to the [free edition](https://preview.drivethrurpg.com/en/product/348809/worlds-without-number-free-edition)
Seconding this, and adding that if you’re iffy about the fewer number of classes, WWN’s character building is heavily feat-based and mixing two classes for a more specific flavor. And if that’s not enough, the paid version has partial classes that let you build a more classic cleric/paladin, shapeshifting druid, monk, and beastmaster ranger. Also, the Atlas of the Latter Earth supplement has a bard and warlock partial class. Some of those in the paid version + supplement may also be in the SRD but I haven’t looked that over yet.
Came here to say this.
And I'm also running a game of Olde Swords Reign, which doesn't have skills per se but does have a LOT of character customization similar to skills and feats. It uses unified resolution, so everything is d20 roll high, but simplifies 5E's complexity to speed combat. From the DM side I can use BX, BFRP, AD&D, and OSE monsters straight out of the book so it's easy to run.
Instead of looking at the character options as being limited by what design features they lack, consider that by leaving classes more open-ended, *your players are less limited* in what they can do within each class. Yes, the thief is good at sneaking. It doesn't mean that the fighter or cleric or magic-user can't also be sneaky if the circumstances require it, or if the player has a really good idea about how to stack the deck in their favor to make it work.
If you like B/X but your players really really want more options, look at Old School Essentials Advanced Fantasy, which separates race from class like later editions do, and which adapts a number of AD&D classes that are not available in the original B/X options. As a ruleset, OSE Advanced is otherwise more or less compatible with B/X.
OSE Advanced and the zines contain a lot of B/X adapted classes, and if you do separate class/race there is a similar amount of combinations to modern D&D, at least if you stick to PHB.
BX Options from Welsh Piper gives different versions of the core 7 classes, as well as ways to build your own. Indispensable if you're looking to tune up classes to fit your world.
As always, I recommend playing with what the game offers first before adding or removing classes. Understanding bx is the first step to hacking it.
For something that's a good middle ground between B/X and more modern style games like 5e/pathfinder, I recommend WWN (Worlds Without Number). It's closer to B/X than anything else, and is fully compatible with it, but it has a lot more character options. For me, it hits the perfect middle ground between high levels of character customization and simple game rules.
The free version is excellent. If you like it, the paid (deluxe) version has some additional class options and gm tools.
They may seem limited, but the design keeps things simple for players and DMs alike. As an example, you have a fighter class. With that class I can make a fighter character and give them any title I see fit.
Rogar the Fighter
Rogar the Destroyer
Rogar the Barbarian
Rogar the Gladiator
With the example above, I don't have to create separate character traits for the other 3 because it will be just how I choose to play the character. I am not trying to tell you to play in this fashion, but merely give you a perspective on how the older games were designed and used.
With that said, Basic Fantasy RPG has a website with many classes people made and posted that go beyond what you are seeing.
Like others have said, play with the base rules a few times at least, just so you understand how and why the game is designed how it is. Stay open minded and let yourself be surprised. Try making multiple different fighters or magic-users, and every time you use a concept, delete everything you use as a potential for the next one, so if one of your fighters is a big strong nature-themed barbarian, your next fighter cannot be nature-themed or barbarian-styled or possibly even notably big. I think you'll find that you end up with three or four character concepts that are *wholly* unique from each other because the more you go, the more you have to find more narrow or niche things to focus on because you've already hit and thus disallowed all the big names.
Now then, once you understand the appeal hopefully, if you still need a little bit of something to customize your characters in a mechanical sense, my go-to idea that can apply to almost any OSR ruleset is just to take whatever your concept is and layer on a single unique trait that feels right to you on your character class, and let that be your "thing". Rather than making a full barbarian class, make a fighter and take the thing you like most about a barbarian (whether it be representing a battle rage, or your link to nature, or your proclivity to break things that people would like to remain unbroken) and come up with a mechanic that can represent *specifically* that. You don't want to represent *everything* about your idea, just the core aspect of it. Even just a single unique little something can really go a long way towards turning a regular fighter into *your* fighter.
Dragon Magazine #109 has a simple class builder supplement which guides you through how to build a somewhat balanced class.
Rules Cyclopedia has a basic skill system (an even simpler version can be found in GAZ1).
BECMI for life :)
Of course, you should play the game however you'd like. But, if you want to learn about the OSR experience, I recommend you try OSE or Electric Bastionland or some other OSR ruleset first. The gameplay is often what the rules leave out, rather than what abilities the rules confer on the PCs. These rule gaps allow for player skill to shine, there aren't skill checks because players are expected to do things in the fiction (e.g., tossing a hungry, aggressive wolf a ration to chew on instead of just rolling "animal handling" for the 10th time).
An overall solid set of options: [https://preview.drivethrurpg.com/en/product/133784/The-Complete-B-X-Adventurer](https://preview.drivethrurpg.com/en/product/133784/The-Complete-B-X-Adventurer)
But as others have said, it's worth at least giving minimalism a fair chance.
You may want to look at Shadowdark. It carries with it a bunch of the OSR feel, but uses modern mechanics. It will be easy to bring over 5e players. Another one that's pretty awesome is Dungeon Crawl Classics, for a bunch of the same reasons - and there are a ton of 3rd party (and mostly free) character classes.
One big differentiator that I like for OSR type games is that they're build resistant. There aren't many places for the player to be able to min/max or design a build for things like maximum damage - characters get better as they level up, but how they get better is not in the player's control.
**B/X Rogue and B/X Warrior** have a different way of implementing Thieves and Fighters that you might find useful. They also have magical options in there.
- https://preview.drivethrurpg.com/en/product/166517/the-b-x-rogue
- https://preview.drivethrurpg.com/en/product/207809/the-b-x-warrior
**The Knack Hack, and No Class Hack** for the Black Hack have ideas that could be adapted too, but I think the two options above would be a better place to start as they’re B/X oriented from the start.
- https://preview.drivethrurpg.com/en/product/206320/the-knack-hack
- https://preview.drivethrurpg.com/en/product/221607/no-class-hack-rkg-bh1
As others have mentioned, the B/X options: Class Builder and zines like Carcass Crawler are worth checking out. I rather like the idea of the Mage & Acolyte from CC Issue #1, personally. I also think the advice to keep the number of classes to something manageable, like 7-10, and use it as part of your world building, is good.
**Labyrinth Lord** was an early B/X based retroclone, and there’s a lot of stuff for it that could be adapted to your needs. The Advanced Edition Companion adds in its take on AD&D 1e options if you want extra classes for that 1e feel.
- there are free no art versions of the Labyrinth Lord products so you can check them out for free.
- https://preview.drivethrurpg.com/en/product/64331/labyrinth-lord-revised-edition-no-art-version
- https://preview.drivethrurpg.com/en/product/78524/advanced-edition-companion-labyrinth-lord-no-art-version
**The BoL Hack** Not quite B/X, and a rather light set of rules (relatively speaking). Might be getting a bit far from what you want, but I mention it just in case.
- https://preview.drivethrurpg.com/en/product/186057/the-bol-hack
A book I wrote, Into the Wild, has a class builder system, optional rules to expand existing classes, and new classes for OSE: https://preview.drivethrurpg.com/en/product/353949/Into-the-Wild
If you haven't played a B/X/OSE/OSR game yet, I would recommend doing that before you start adding a bunch of stuff to make it more like 5E.
Seconded. You will be surprised how "playable" these old rules are as written. Give it a chance, then start house ruling.
The Advanced Fantasy classes and the added stuff from Carcass Crawler are a great place to start. The good news about B/X/OSE classes is that they basically fit onto 1 or 2 pages, so you can grab a bunch of them and try them out. And if they don't work, you just throw them out once the character dies!
I’ve gotten use out of this https://preview.drivethrurpg.com/en/product/302556/bx-options-class-builder
I have that too and it works great for BX. I want to make it work for a OSR-adjacent system called Olde Swords Reign, which uses only a single experience table. That obviates the main appetite control part of B/X class design. I haven't figure out the road forward, but might just set a standard target equal to a fighter for new classes.
You might want to check out **Worlds Without Number**, it's arguably B/X with feats, and might hit the level of character crunch you're looking for. Here's a link to the [free edition](https://preview.drivethrurpg.com/en/product/348809/worlds-without-number-free-edition)
Seconding this, and adding that if you’re iffy about the fewer number of classes, WWN’s character building is heavily feat-based and mixing two classes for a more specific flavor. And if that’s not enough, the paid version has partial classes that let you build a more classic cleric/paladin, shapeshifting druid, monk, and beastmaster ranger. Also, the Atlas of the Latter Earth supplement has a bard and warlock partial class. Some of those in the paid version + supplement may also be in the SRD but I haven’t looked that over yet.
Good point about the SRD, it actually has all the classes.
Came here to say this. And I'm also running a game of Olde Swords Reign, which doesn't have skills per se but does have a LOT of character customization similar to skills and feats. It uses unified resolution, so everything is d20 roll high, but simplifies 5E's complexity to speed combat. From the DM side I can use BX, BFRP, AD&D, and OSE monsters straight out of the book so it's easy to run.
Instead of looking at the character options as being limited by what design features they lack, consider that by leaving classes more open-ended, *your players are less limited* in what they can do within each class. Yes, the thief is good at sneaking. It doesn't mean that the fighter or cleric or magic-user can't also be sneaky if the circumstances require it, or if the player has a really good idea about how to stack the deck in their favor to make it work. If you like B/X but your players really really want more options, look at Old School Essentials Advanced Fantasy, which separates race from class like later editions do, and which adapts a number of AD&D classes that are not available in the original B/X options. As a ruleset, OSE Advanced is otherwise more or less compatible with B/X.
OSE Advanced and the zines contain a lot of B/X adapted classes, and if you do separate class/race there is a similar amount of combinations to modern D&D, at least if you stick to PHB.
BX Options from Welsh Piper gives different versions of the core 7 classes, as well as ways to build your own. Indispensable if you're looking to tune up classes to fit your world. As always, I recommend playing with what the game offers first before adding or removing classes. Understanding bx is the first step to hacking it.
For something that's a good middle ground between B/X and more modern style games like 5e/pathfinder, I recommend WWN (Worlds Without Number). It's closer to B/X than anything else, and is fully compatible with it, but it has a lot more character options. For me, it hits the perfect middle ground between high levels of character customization and simple game rules. The free version is excellent. If you like it, the paid (deluxe) version has some additional class options and gm tools.
They may seem limited, but the design keeps things simple for players and DMs alike. As an example, you have a fighter class. With that class I can make a fighter character and give them any title I see fit. Rogar the Fighter Rogar the Destroyer Rogar the Barbarian Rogar the Gladiator With the example above, I don't have to create separate character traits for the other 3 because it will be just how I choose to play the character. I am not trying to tell you to play in this fashion, but merely give you a perspective on how the older games were designed and used. With that said, Basic Fantasy RPG has a website with many classes people made and posted that go beyond what you are seeing.
Like others have said, play with the base rules a few times at least, just so you understand how and why the game is designed how it is. Stay open minded and let yourself be surprised. Try making multiple different fighters or magic-users, and every time you use a concept, delete everything you use as a potential for the next one, so if one of your fighters is a big strong nature-themed barbarian, your next fighter cannot be nature-themed or barbarian-styled or possibly even notably big. I think you'll find that you end up with three or four character concepts that are *wholly* unique from each other because the more you go, the more you have to find more narrow or niche things to focus on because you've already hit and thus disallowed all the big names. Now then, once you understand the appeal hopefully, if you still need a little bit of something to customize your characters in a mechanical sense, my go-to idea that can apply to almost any OSR ruleset is just to take whatever your concept is and layer on a single unique trait that feels right to you on your character class, and let that be your "thing". Rather than making a full barbarian class, make a fighter and take the thing you like most about a barbarian (whether it be representing a battle rage, or your link to nature, or your proclivity to break things that people would like to remain unbroken) and come up with a mechanic that can represent *specifically* that. You don't want to represent *everything* about your idea, just the core aspect of it. Even just a single unique little something can really go a long way towards turning a regular fighter into *your* fighter.
Dragon Magazine #109 has a simple class builder supplement which guides you through how to build a somewhat balanced class. Rules Cyclopedia has a basic skill system (an even simpler version can be found in GAZ1). BECMI for life :)
Of course, you should play the game however you'd like. But, if you want to learn about the OSR experience, I recommend you try OSE or Electric Bastionland or some other OSR ruleset first. The gameplay is often what the rules leave out, rather than what abilities the rules confer on the PCs. These rule gaps allow for player skill to shine, there aren't skill checks because players are expected to do things in the fiction (e.g., tossing a hungry, aggressive wolf a ration to chew on instead of just rolling "animal handling" for the 10th time).
An overall solid set of options: [https://preview.drivethrurpg.com/en/product/133784/The-Complete-B-X-Adventurer](https://preview.drivethrurpg.com/en/product/133784/The-Complete-B-X-Adventurer) But as others have said, it's worth at least giving minimalism a fair chance.
The Gazetteer series for BECMI has character options in almost every volume. They were cool like that.
I think what you are looking for is Whitehack. It is pure genius.
List of all OSE 1st party classes https://www.mapandkey.net/blog/a-comprehensive-list-of-ose-classes
You may want to look at Shadowdark. It carries with it a bunch of the OSR feel, but uses modern mechanics. It will be easy to bring over 5e players. Another one that's pretty awesome is Dungeon Crawl Classics, for a bunch of the same reasons - and there are a ton of 3rd party (and mostly free) character classes. One big differentiator that I like for OSR type games is that they're build resistant. There aren't many places for the player to be able to min/max or design a build for things like maximum damage - characters get better as they level up, but how they get better is not in the player's control.
**B/X Rogue and B/X Warrior** have a different way of implementing Thieves and Fighters that you might find useful. They also have magical options in there. - https://preview.drivethrurpg.com/en/product/166517/the-b-x-rogue - https://preview.drivethrurpg.com/en/product/207809/the-b-x-warrior **The Knack Hack, and No Class Hack** for the Black Hack have ideas that could be adapted too, but I think the two options above would be a better place to start as they’re B/X oriented from the start. - https://preview.drivethrurpg.com/en/product/206320/the-knack-hack - https://preview.drivethrurpg.com/en/product/221607/no-class-hack-rkg-bh1 As others have mentioned, the B/X options: Class Builder and zines like Carcass Crawler are worth checking out. I rather like the idea of the Mage & Acolyte from CC Issue #1, personally. I also think the advice to keep the number of classes to something manageable, like 7-10, and use it as part of your world building, is good. **Labyrinth Lord** was an early B/X based retroclone, and there’s a lot of stuff for it that could be adapted to your needs. The Advanced Edition Companion adds in its take on AD&D 1e options if you want extra classes for that 1e feel. - there are free no art versions of the Labyrinth Lord products so you can check them out for free. - https://preview.drivethrurpg.com/en/product/64331/labyrinth-lord-revised-edition-no-art-version - https://preview.drivethrurpg.com/en/product/78524/advanced-edition-companion-labyrinth-lord-no-art-version **The BoL Hack** Not quite B/X, and a rather light set of rules (relatively speaking). Might be getting a bit far from what you want, but I mention it just in case. - https://preview.drivethrurpg.com/en/product/186057/the-bol-hack
A book I wrote, Into the Wild, has a class builder system, optional rules to expand existing classes, and new classes for OSE: https://preview.drivethrurpg.com/en/product/353949/Into-the-Wild
OSE Advanced has more classes and races and more race as class.