My general take is to assume module author competence; that the author is familiar with the system that they're writing for and that they playtested the module in the system that it was written for.
Even if they didn't playtest, by nature of the module being recommended by other folks, they've done additional playtesting, and often write up thoughts on what works and what doesn't.
When you play the module in a different system with different underlying math, you're now playing something that's less playtested, and so you'll run into more rough edges. For low level modules, I think this comes up *very* often with ghouls.
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In B/X, a ghoul hits a plate-wearing level 1 front-liner on a 16+ (25% of the time). It attacks 3x per turn, so you expect 0.75 hits per turn for an average of 1.5 damage. First level clerics turn ghouls on an 11-in-2d6, which is 8% of the time, and they can cast turn undead every combat round. Meanwhile, in 1e, Ghouls hit banded+shield turn on a 13+ (40%). Their bite does 1d6 damage instead of 1d3. They're now hitting 1.2x per turn for 3 expected damage a turn, so they're fully doing twice as much damage in 1e as in BX.
Finally, OSE uses different frontage rules; enemies occupy a standard space in a 5' grid, so only two ghouls can attack the front line in a standard hallway. In 1e, there's a whole space required system, so if your GM rules that unarmed humanoids use 2' of frontage then the front line is getting attacked by 5 ghouls, and if it's 3' of frontage then the front lie is getting attacked by 3 ghouls. The net here is that ghouls are putting out somewhere between 3x and 5x more damage per round in 1e than in OSE. Fighting ghouls is going to feel **very different** in 1e than B/X.
An encounter against 5 ghouls might be a tough-ish dangerous fight in B/X, but those same 5 ghouls might be an extremely-likely-tpk in 1e, and so now one of the choices (fight but get taxed hp/spells/etc) has been *removed*. If the ghouls are in some sort of important path in the module (blocking the way to valuable treasure, an important clue, valuable magic item, etc) then now the module will *feel different*.
---
A general note is that every time we play a game in a different system, we're *translating*. Translated books/movies/etc are *not* the same as the original; nuance will always get lost. The more precise and nuanced the dialog is (especially books that "play" with language), the more gets lost. I think this is exactly what happens with translating adventures between systems.
Excellent analysis! I think people do underestimate how the feeling of play can shift as these probabilities shift, with the result is that playing across systems is less compatible than people think. It is a translation, as you say, and benefits from the GM taking some time to figure out where things will play much differently from intended rather than just trying to convert on the fly or using the same values but getting different results.
By the way I'd love to see you do a deep dive on Shadowdark in particular, given how popular it's become.
- advantage/disadvantage is a good system, better than modifiers imo
I don't like
- roll to cast
- the xp system (causes conversion overhead)
- the DC system (I *really* don't like coming up with DCs)
- the keywording consistency is rough
- attributes scores (which you don't control) are much more important than in BX
- backstab is not defined
- I'm never a fan of when a game says "pick a background, and have the GM use fiat to determine if it helps somehow". In play, I find this results in annoying mother-may-i style negotiation. I prefer for characters to have a background in adventuring (which should be a real profession in these sorts of worlds), and for past careers to be RP flavor.
- I don't like the luck metacurrency
- I don't like the carousing rules (require lots of gm improv)
A related experience I've had recently: running S1 Tomb of Horrors using Swords & Wizardry (Complete Revised). S1 was published for AD&D 1E, of course, while S&W is an OD&D retroclone. So precise compatibility is not to be expected. I went with S&W for a few reasons, one of which was that it appeared to be *basically* compatible.
There were two conversions I had to make, to meet my goal of fidelity to the "original experience" (as presented in the module text): stats for the custom monsters in S1's key... and saving throws. I initially thought I could leave the saving throws alone, so long as I used the alternate 5 saves instead of S&W's unified mechanic option.
But then I took a closer look and realized that the 0e/S&W saves were *much better* than the 1E saves, giving up to 15-20% better odds of surviving, say, the save-or-die poison spikes in S1s pit traps. So I simply swapped out the S&W saves for the 1E saves, right from the AD&D rulebooks.
I tell that story because I think it speaks to the point about numbers mattering - but also an aspect of "compatibility" that you didn't touch on, which is modularity. When the systems share that lingua franca, or are built on a similar skeleton with similar design intent, that can let you replace bits and pieces pretty ad hoc, without breaking the rest of the game.
(And I'd suggest that aspect is how we can describe the 0e thru 2e D&D editions as "broadly compatible", in a way that the post-D20 System editions aren't.)
Maybe the monster has 18 dex and a magic item to get that 20 AC.
Still not to scale for the avg 3rd lvl fighter. But then again, your 3rd lvl fighter is dumb for getting into a 1v1 on a 6HD monster if he can help it.
But that's the thing, careful balance isn't the point. Have the MU hit that 20 AC threat with slow, have the cleric cast continual light on its eyes. Did the thief bring plenty of Oil? AC 9 (10) now to light that sucker up.
Man I love playing Pathfinder, it's technically compatible with 3e and therefore 2e and thus B/X. AC 87 is where I personally start to draw the line for scale issues regarding the word comparable.
Dragonbane which I've been on spree of? Man I'd say it's compatible with anything where monsters have fewer than 100 HP and uses a 3-18 attribute system like we all know and love.
Hackmaster is another odd case, just kick everything back down 20 HP and your basically done, minus everything else.
A stat block is just the average statistics. The slight difference between minotaurs? That OSE one is only an uncommon, everyone knows Legendary monsters drop the best loot.
Thinking about one such encounter, I needed to find another two shoes of speed for my horse but the breastplate of blinding was a hit with the cleric. The +2 axe went to the fighter. The mage died under a charge attack from horseshoes of speed.
The system? Labyrinth Lord. The module? The GM's remix of a Hackmaster remix of B2.
Balance? Zero. Possibility of being B/X not only possible but play as intended? 100%.
Temple of the Frog has its magic rings and that is about as early and official as how as it gets.
I think your right, but I think it was more common in the older era of TTRPGs and so the skill was practiced and honed while it has become more lost with time.
I always point to anything by Jennell Jaquays as the example of this. When we look at things like Borshak's Lair and Walking Wet or Caverns we see a lot of things that would have sent the rule lawyers of the time into a fit and yet Caverns might be the most popular non TSR module ever published.
I think that the older DM rule books having so much emphasis on statistics was a benefit that we took for granted.
Gary said the worst thing for the business would be if DMs realized they didn't need rulebooks.
Wizards has clearly built their business on selling rulebooks and their modules are not exactly frequent.
Hello, very interesting reading! Your digression on B/X compatibility turned on my interest as I plan since some time to have a conversion of 3 simple adventures into b/x (or a generic OSR). Would you be open to discuss about the conversion and provide me with an advice? Thanks a lot and ciaoo
It seems that there is much handwringing about how “minor statistical differences” create different outcomes at the table. This reflects a broader conflation of “compatibility” with “no variation of outcomes.”
Compatibility means that the pieces from one game will work in another. Not that they will work exactly the same, just that they will work. You can run KotB in SD straight from the page and get a good game. Will the SD PCs get an advantage? Yes, but the GM doesn’t have to do any extra work to make it happen. Will it be fun and challenging? Unless the players are hyper critical game designers, they will probably have tons of fun and not even notice there could have been a “difference.”
Put a SD Minotaur in front of a B/X party for a slightly higher challenge. The players only know there is a Minotaur.
Nice read! What about the Minotaur? Does his hit probability also go up? Too me it always feels like Shadowdark at least at lower levels is more violent. At higher levels I think Shadowdark becomes too easy, so I tend to stop at level 5.
Thanks for the shout!
My general take is to assume module author competence; that the author is familiar with the system that they're writing for and that they playtested the module in the system that it was written for.
Even if they didn't playtest, by nature of the module being recommended by other folks, they've done additional playtesting, and often write up thoughts on what works and what doesn't.
When you play the module in a different system with different underlying math, you're now playing something that's less playtested, and so you'll run into more rough edges. For low level modules, I think this comes up *very* often with ghouls.
---
In B/X, a ghoul hits a plate-wearing level 1 front-liner on a 16+ (25% of the time). It attacks 3x per turn, so you expect 0.75 hits per turn for an average of 1.5 damage. First level clerics turn ghouls on an 11-in-2d6, which is 8% of the time, and they can cast turn undead every combat round. Meanwhile, in 1e, Ghouls hit banded+shield turn on a 13+ (40%). Their bite does 1d6 damage instead of 1d3. They're now hitting 1.2x per turn for 3 expected damage a turn, so they're fully doing twice as much damage in 1e as in BX.
Finally, OSE uses different frontage rules; enemies occupy a standard space in a 5' grid, so only two ghouls can attack the front line in a standard hallway. In 1e, there's a whole space required system, so if your GM rules that unarmed humanoids use 2' of frontage then the front line is getting attacked by 5 ghouls, and if it's 3' of frontage then the front lie is getting attacked by 3 ghouls. The net here is that ghouls are putting out somewhere between 3x and 5x more damage per round in 1e than in OSE. Fighting ghouls is going to feel **very different** in 1e than B/X.
An encounter against 5 ghouls might be a tough-ish dangerous fight in B/X, but those same 5 ghouls might be an extremely-likely-tpk in 1e, and so now one of the choices (fight but get taxed hp/spells/etc) has been *removed*. If the ghouls are in some sort of important path in the module (blocking the way to valuable treasure, an important clue, valuable magic item, etc) then now the module will *feel different*.
---
A general note is that every time we play a game in a different system, we're *translating*. Translated books/movies/etc are *not* the same as the original; nuance will always get lost. The more precise and nuanced the dialog is (especially books that "play" with language), the more gets lost. I think this is exactly what happens with translating adventures between systems.
Excellent analysis! I think people do underestimate how the feeling of play can shift as these probabilities shift, with the result is that playing across systems is less compatible than people think. It is a translation, as you say, and benefits from the GM taking some time to figure out where things will play much differently from intended rather than just trying to convert on the fly or using the same values but getting different results.
By the way I'd love to see you do a deep dive on Shadowdark in particular, given how popular it's become.
> I'd love to see you do a deep dive on Shadowdark in particular, given how popular it's become.
I wrote up some shadowdark thoughts here: https://rancourt.substack.com/p/review-old-school-essentials/comment/70397088
From a cursory read...
I like:
- class progression via random talents
- no one has darkvision
- advantage/disadvantage is a good system, better than modifiers imo
I don't like
- roll to cast
- the xp system (causes conversion overhead)
- the DC system (I *really* don't like coming up with DCs)
- the keywording consistency is rough
- attributes scores (which you don't control) are much more important than in BX
- backstab is not defined
- I'm never a fan of when a game says "pick a background, and have the GM use fiat to determine if it helps somehow". In play, I find this results in annoying mother-may-i style negotiation. I prefer for characters to have a background in adventuring (which should be a real profession in these sorts of worlds), and for past careers to be RP flavor.
- I don't like the luck metacurrency
- I don't like the carousing rules (require lots of gm improv)
I don't forsee myself playing shadowdark, so I probably won't write an in-depth review for it, but I think scholomance did a great job: https://scholomance.substack.com/p/tabletop-review-shadowdark-rpg-by
A reasonable conclusion, all around!
A related experience I've had recently: running S1 Tomb of Horrors using Swords & Wizardry (Complete Revised). S1 was published for AD&D 1E, of course, while S&W is an OD&D retroclone. So precise compatibility is not to be expected. I went with S&W for a few reasons, one of which was that it appeared to be *basically* compatible.
There were two conversions I had to make, to meet my goal of fidelity to the "original experience" (as presented in the module text): stats for the custom monsters in S1's key... and saving throws. I initially thought I could leave the saving throws alone, so long as I used the alternate 5 saves instead of S&W's unified mechanic option.
But then I took a closer look and realized that the 0e/S&W saves were *much better* than the 1E saves, giving up to 15-20% better odds of surviving, say, the save-or-die poison spikes in S1s pit traps. So I simply swapped out the S&W saves for the 1E saves, right from the AD&D rulebooks.
I tell that story because I think it speaks to the point about numbers mattering - but also an aspect of "compatibility" that you didn't touch on, which is modularity. When the systems share that lingua franca, or are built on a similar skeleton with similar design intent, that can let you replace bits and pieces pretty ad hoc, without breaking the rest of the game.
(And I'd suggest that aspect is how we can describe the 0e thru 2e D&D editions as "broadly compatible", in a way that the post-D20 System editions aren't.)
I like the variation because it keeps players on their toes. All monsters generally have the same style of attacks and defense.
Also why didn’t the OSE fighter get any bonuses for 16 STR and Lvl 3?
Also OSE has notoriously shitty fighters
Maybe the monster has 18 dex and a magic item to get that 20 AC.
Still not to scale for the avg 3rd lvl fighter. But then again, your 3rd lvl fighter is dumb for getting into a 1v1 on a 6HD monster if he can help it.
But that's the thing, careful balance isn't the point. Have the MU hit that 20 AC threat with slow, have the cleric cast continual light on its eyes. Did the thief bring plenty of Oil? AC 9 (10) now to light that sucker up.
Man I love playing Pathfinder, it's technically compatible with 3e and therefore 2e and thus B/X. AC 87 is where I personally start to draw the line for scale issues regarding the word comparable.
Dragonbane which I've been on spree of? Man I'd say it's compatible with anything where monsters have fewer than 100 HP and uses a 3-18 attribute system like we all know and love.
Hackmaster is another odd case, just kick everything back down 20 HP and your basically done, minus everything else.
A stat block is just the average statistics. The slight difference between minotaurs? That OSE one is only an uncommon, everyone knows Legendary monsters drop the best loot.
Thinking about one such encounter, I needed to find another two shoes of speed for my horse but the breastplate of blinding was a hit with the cleric. The +2 axe went to the fighter. The mage died under a charge attack from horseshoes of speed.
The system? Labyrinth Lord. The module? The GM's remix of a Hackmaster remix of B2.
Balance? Zero. Possibility of being B/X not only possible but play as intended? 100%.
Temple of the Frog has its magic rings and that is about as early and official as how as it gets.
This is one approach that people take! I think it takes some experience as a GM to alter things on the fly like that
I think your right, but I think it was more common in the older era of TTRPGs and so the skill was practiced and honed while it has become more lost with time.
I always point to anything by Jennell Jaquays as the example of this. When we look at things like Borshak's Lair and Walking Wet or Caverns we see a lot of things that would have sent the rule lawyers of the time into a fit and yet Caverns might be the most popular non TSR module ever published.
I think that the older DM rule books having so much emphasis on statistics was a benefit that we took for granted.
Gary said the worst thing for the business would be if DMs realized they didn't need rulebooks.
Wizards has clearly built their business on selling rulebooks and their modules are not exactly frequent.
But these are just my hot takes.
Hello, very interesting reading! Your digression on B/X compatibility turned on my interest as I plan since some time to have a conversion of 3 simple adventures into b/x (or a generic OSR). Would you be open to discuss about the conversion and provide me with an advice? Thanks a lot and ciaoo
It seems that there is much handwringing about how “minor statistical differences” create different outcomes at the table. This reflects a broader conflation of “compatibility” with “no variation of outcomes.”
Compatibility means that the pieces from one game will work in another. Not that they will work exactly the same, just that they will work. You can run KotB in SD straight from the page and get a good game. Will the SD PCs get an advantage? Yes, but the GM doesn’t have to do any extra work to make it happen. Will it be fun and challenging? Unless the players are hyper critical game designers, they will probably have tons of fun and not even notice there could have been a “difference.”
Put a SD Minotaur in front of a B/X party for a slightly higher challenge. The players only know there is a Minotaur.
Nice read! What about the Minotaur? Does his hit probability also go up? Too me it always feels like Shadowdark at least at lower levels is more violent. At higher levels I think Shadowdark becomes too easy, so I tend to stop at level 5.