So I was thinking about how to break down published D&D/OSR adventure modules into categories based on how they are structured/themed. This isn't about which category is best, but about how to group them.

1) Pure dungeon crawl: This is essentially keyed locations with a scattering of monsters to fight and treasure to collect, like B1 "In Search of the Unknown". There can be background and logic to the layout, but the assumption for context is that the adventurers are there to kill the monsters and collect the treasure.

2) Dungeon mission: These are somewhat more focused location where the PCs are facing some potentially organized opposition. There can be various side encounters. I'm thinking especially of "Against the Giants" series and later. The adventure is one large location that is an active lair for a specific set of opposition to be overcome. I'm not sure if the 3E module "The Sunless Citadel" would be in this or should be split out because it has three sets of active opposition (kobolds, goblins, and the villainous druid).

3) City modules: These usually have a bunch of locations that just describe an interesting but ordinary working community. Those locations can be the scene of some different missions, like hidden gangs or cults, or secret monsters, that are dynamically run by the DM. I'm not sure what the classic city modules are, but I think of Lankhmar.

4) Tournament modules: These are somewhat more structured than pure dungeon crawl as a series of challenges to overcome - usually mixing in some puzzles, tricks, traps, and riddles. It doesn't have active opposition, but has very fixed challenge points to be judged in tournaments. There can be some taken in varying order, but they generally funnel to a common final encounter. I think of The Ghost Tower of Inverness or Egg of the Phoenix. Classic tournaments often had a point system for how players did against each challenge.

5) Dungeon story modules: I think I6 Ravenloft is the template for this. It is similar to mission in that there is a location with a bunch of opposition including active elements. It has more overlay of elements to it, though, with possible secrets to unlock and subplots to explore that go beyond just opposition to the mission.

6) Storyline modules: These are mission based, with a number of separate locations each leading to the next, and usually at least one prepared scene for each often with boxed text. I understand that the Dragonlance modules pioneered this, but I know of the style from the later Ravenloft demi-plane modules. I think of RM3 Web of Illusion as the one I'm most familiar with, but I largely avoided these.

7) Adventure path modules: This is a later development, I think, of having multiple locations that connect. Each is usually more than a scene - and can often be a small keyed dungeon. Still, each generally leads to the next in a mostly linear fashion, though there can be limited choice or variation. I think this started in 3E, but what comes to mind for me is The Lost Mine of Phandelver for 5E.

I'm sure there's more I'm skipping, of course. This is intended as a first pass for comment.

Setting Modules - Caves of Chaos is the obvious choice.  Sure, there's a lot of overlap with the first two, but the focus is on providing an environment where the players mostly set their own "mission". 

I would say that the primary difference is that there are not typically canned "events" but there are NPCs/monsters with an agenda that can obviously lead to various events if the GM is so inclined and/or the players push the right buttons.

Quote from: jhkim on November 16, 2022, 05:46:51 PM

7) Adventure path modules: This is a later development, I think, of having multiple locations that connect. Each is usually more than a scene - and can often be a small keyed dungeon. Still, each generally leads to the next in a mostly linear fashion, though there can be limited choice or variation. I think this started in 3E, but what comes to mind for me is The Lost Mine of Phandelver for 5E.

Yes, I haven't found anything similar to this, either OS or OSR.

Going one step further, there are 5e modules like Curse of Strahd and ToA that have no clear linear progression, just a beginning, an ending, and a sandbox in the middle. This is my favorite kind of adventure, TBH, but they are few and still not great (badly organized etc.).

I would say that what you're calling Adventure Path modules started with some of the Expert modules in the 80s, as well as nearly all of the Companion and Master level adventures.  Certainly X4, X5, X10, X11, and X13 fit this description.

the GDQ series is the first of the "Adventure Path" module types. It takes a single plot thread "Giant Invasion" and extraploates that into a global invasion by extra planar demons.

Quote from: Persimmon on November 16, 2022, 09:11:03 PM
I would say that what you're calling Adventure Path modules started with some of the Expert modules in the 80s, as well as nearly all of the Companion and Master level adventures.  Certainly X4, X5, X10, X11, and X13 fit this description.

Quote from: THE_Leopold on November 17, 2022, 09:20:22 AM
the GDQ series is the first of the "Adventure Path" module types. It takes a single plot thread "Giant Invasion" and extraploates that into a global invasion by extra planar demons.

I see the point, but GDQ is distinct from the later adventure paths in that each step in the path is bigger. Obviously that's a fuzzy line - i.e. how big do the steps have to be for it to be an adventure path? The first step G1 is 8 pages and 58 locations, for example.

The steps in what I think of as adventure paths are usually shorter. I think I'd agree with Persimmon that X4 is similar to the later adventure paths. There are six parts in a 32-page module each connected to the next, and most of those parts are 2-4 pages, though the last is longer and is equivalent to G1. But it also has more plot to it in that there is a mystery to solve in dealing with the abbey. I haven't looked at the later modules.

The Lost Mine of Phandelver has 11 steps in a 50-page module, but the page count per encounter is greater because of stuff like boxed text and DM advice. Most of the steps in it are much shorter than something like G1, with only the last step being close - with 20 locations in 7 pages.

I'm not sure I'd combine structure and environment (City) in the same categorization level, but if you do, then I'd consider Village/Rural adventures different from City/Urban ones. And then there are the Midsummer Night's enchanted forest druid grove-y faun-and-unicorn Wilderness adventures that are distinct from both.

Monster hunts might be another category

Quote from: Horace on November 17, 2022, 11:17:25 AM
I'm not sure I'd combine structure and environment (City) in the same categorization level, but if you do, then I'd consider Village/Rural adventures different from City/Urban ones. And then there are the Midsummer Night's enchanted forest druid grove-y faun-and-unicorn Wilderness adventures that are distinct from both.

I was intending to be by structure rather than environment, so "city" is a misnomer - but it's based on a common case. I'd class Village of Hommlet as similar.

The point is that there are a bunch of locations, but most of the locations are background rather than adventure encounters. Also, they can be encountered in any order since they're scattered around the map rather than having dungeon-like connections between them.

Quote from: Bedrockbrendan on November 17, 2022, 12:07:25 PM
Monster hunts might be another category

Can you give some examples of modules you'd consider in this category?

Quote from: jhkim on November 17, 2022, 12:12:50 PM

Quote from: Bedrockbrendan on November 17, 2022, 12:07:25 PM
Monster hunts might be another category

Can you give some examples of modules you'd consider in this category?

I am actually having trouble thinking of a D&D module that did it (but I feel like I remember them). I know the Van Richten guides, which were supplements, not modules, described ways of playing and gave examples that very much felt like monster hunts.

Quote from: Steven Mitchell on November 16, 2022, 07:48:11 PM
Setting Modules - Caves of Chaos is the obvious choice.  Sure, there's a lot of overlap with the first two, but the focus is on providing an environment where the players mostly set their own "mission". 

I would say that the primary difference is that there are not typically canned "events" but there are NPCs/monsters with an agenda that can obviously lead to various events if the GM is so inclined and/or the players push the right buttons.

Potentially organized opposition is part what I classify as my "dungeon mission" category, like G1 where the GM can have the giants organize and respond to attack.

Though you're right that the Caves of Chaos isn't appropriately called a "mission", though, and it has multiple sets of potentially organized opposition. I suppose this should really be its own category, and I'd include "The Sunless Citadel" into the same category for its three sets of opposition.

I don't like the name "Setting Modules", though, because all modules have a setting. What distinguishes this to my mind is having multiple sets of potentially-organized and potentially-conflicting opposition, but the material is still mostly presented as keyed locations.

Quote from: Bedrockbrendan on November 17, 2022, 12:24:31 PM

Quote from: jhkim on November 17, 2022, 12:12:50 PM

Quote from: Bedrockbrendan on November 17, 2022, 12:07:25 PM
Monster hunts might be another category

Can you give some examples of modules you'd consider in this category?

I am actually having trouble thinking of a D&D module that did it (but I feel like I remember them). I know the Van Richten guides, which were supplements, not modules, described ways of playing and gave examples that very much felt like monster hunts.

The Shadow Chasers mini-game, sadly it's for d20Modern.

Quote from: GeekyBugle on November 17, 2022, 04:30:42 PM

Quote from: Bedrockbrendan on November 17, 2022, 12:24:31 PM
I am actually having trouble thinking of a D&D module that did it (but I feel like I remember them). I know the Van Richten guides, which were supplements, not modules, described ways of playing and gave examples that very much felt like monster hunts.

The Shadow Chasers mini-game, sadly it's for d20Modern.

Sounds interesting, but rare enough that it's not really a genre. From non-D&D adventures, I can think of several other module types. I don't know of examples of them in D&D.

9) Pure dynamic-opponent modules: I think of this mainly from some superhero modules. There are locations described, but there are few or no fixed encounters for these. Instead, there are NPC opponents who are described and who will move and act as the GM plans. This is similar to some city modules, but the locations are scattered based on the NPC plans. So the primary material in the module is the NPC villains and their plans, who the GM must have move and act.

10) Timetable mission modules: I think of this mainly from mystery and/or espionage modules, like Top Secret's "Operation Fastpass". There are a set of events laid out in date and time of what will happen if the PCs do not interfere. Depending on where the PCs are at a given time, they might encounter some of the events and change them. This could change later plans. There will also be locations and NPCs described, but the main action is dynamic according to the timetable rather than encounters based on location.

11) Story assembly-piece modules: This also seems like more of a superhero module thing. There are story elements that are outlined to be assembled - like descriptions of subplots, twists, and so forth that the GM has to assemble together. There will be dynamic NPCs and locations as well, but how they fit together depends on how the GM assembles the plot pieces. So there might be a section on a possible romantic subplot, and it's up to the GM how to work it in. I think of "The Coriolis Effect" or "The Great Supervillain Contest" for Champions as examples.

Quote from: jhkim on November 17, 2022, 05:39:27 PM

Quote from: GeekyBugle on November 17, 2022, 04:30:42 PM

Quote from: Bedrockbrendan on November 17, 2022, 12:24:31 PM
I am actually having trouble thinking of a D&D module that did it (but I feel like I remember them). I know the Van Richten guides, which were supplements, not modules, described ways of playing and gave examples that very much felt like monster hunts.

The Shadow Chasers mini-game, sadly it's for d20Modern.

Sounds interesting, but rare enough that it's not really a genre. From non-D&D adventures, I can think of several other module types. I don't know of examples of them in D&D.

9) Pure dynamic-opponent modules: I think of this mainly from some superhero modules. There are locations described, but there are few or no fixed encounters for these. Instead, there are NPC opponents who are described and who will move and act as the GM plans. This is similar to some city modules, but the locations are scattered based on the NPC plans. So the primary material in the module is the NPC villains and their plans, who the GM must have move and act.

10) Timetable mission modules: I think of this mainly from mystery and/or espionage modules, like Top Secret's "Operation Fastpass". There are a set of events laid out in date and time of what will happen if the PCs do not interfere. Depending on where the PCs are at a given time, they might encounter some of the events and change them. This could change later plans. There will also be locations and NPCs described, but the main action is dynamic according to the timetable rather than encounters based on location.

11) Story assembly-piece modules: This also seems like more of a superhero module thing. There are story elements that are outlined to be assembled - like descriptions of subplots, twists, and so forth that the GM has to assemble together. There will be dynamic NPCs and locations as well, but how they fit together depends on how the GM assembles the plot pieces. So there might be a section on a possible romantic subplot, and it's up to the GM how to work it in. I think of "The Coriolis Effect" or "The Great Supervillain Contest" for Champions as examples.

Well, I'm "working" on an OSR Monster Hunting game, think I'll have it ready on time to publish for next Halloween.