Zardnaar
Legend
If you go back and look at some older adventures from the 80's and pages of Dungeon magazine in the AD&D era there are several tropes that are rare/extinct in modern D&D. These tropes still turn up OSR products and sometimes Pathfinder and 3pp adventures.Can 5E do these old tropes justice? IDK but I have at least tried a few over the last few years. Surprisingly despite how notorious Tomb of Horrors its not a particularly strong OSR trope as Tomb Horrors is semi unique in AD&D with perhaps the Labyrinth of Madness being close in terms of deadliness. Most of the current WotC FR AP's are based inn the Sword Coast region.
1. Magical Fountains
Old adventures such as B5 Horror on the Hill often have a magical fountain or water source in a forest that has a magical effect. These are often healing or random effect based with sometimes a negative effect. You might be healed, gain a boost to an ability score or be poisoned etc. I have seen things like this turn up in Castles and Crusades products and the Pathfinder Kingmaker adventure path or conversions of 3pp to 5E (Quests of Doom, Troll Lord Games C&C conversions to 5E etc).
2. Hexcrawls
Hexcrawls were not a massive part of AD&D but they did turn up in several X series of of adventures. The most famous is X1 The Isle of Dread but they also used them in Quagmire, Master of the Desert Nomads and War Rafts of Kron for example. They usually feature things like keyed locations and wandering monster tables. 5E has attempted this on a smaller scale with Princes of the Apocalypse but the 6-8 encounter expectation and overall nerfing of monsters makes it a bit harder in 5E (eg Wyverns are no longer save or die). The Stolen Lands (pt 1 Kingmaker AP Pathfinder) is another example of a hexcrawl that I think could be adapted to 5E. You would probably have to use some stronger monsters on random encounter tables and have more keyed locations (small dungeons and encounter areas) to make it work. Granting xp or milestone rewards for exploring hexes is another idea. Older hexcrawls were often an island or continent wide in scale.
3. Underwater Adventures.
Not to many published adventures are an underwater adventure module but they turn up fairly frequently in old Dungeon magazines. They are generally for level 3-6 ish PCs set before they can reliably cast water breathing spells. Often NPCs supply potions of healing. Sometimes they are combined with a hexcrawl and something like an undersea boat or other submersible is provided. The War Rafts of Kron is set mostly underwater that allows you to explore the bottom of the Sea of Dread and is a higher level adventure (9-12). Its also interesting to see how they structured encounters back then to challenge high level PCs. An encounter with 4 Triton wizards each packing lighting bolt riding giant sea horses is an interesting idea IMHO.
4. Environment Adventures.
Remember Sandstorm and Frostburn books in 3.5? They were nothing new with old adventures such as B4 The Lost City, Pharaoh, Desert of Desolation series featuring deserts while arctic adventures often cropped up in Dungeon magazine. Darksun is also this idea turned up to 10. For whatever reason deserts seem more popular than arctic adventures probably because there are numerous examples of ruins in places like Egypt, Iraq, Syria, Tunis etc.
5. Real Life Cultures
This is generally fantasy versions of Egypt, Rome, Greece, Aztecs, Olmecs, China and Japan. The Realms have several of these tropes along with Golarion and the Kobolds Midguard and Southland settings. The poster child for this however is Mystara/The Known World which has fantasy Romans, Egyptians, Greeks, France, Italian city states, Arabs, Vikings, Mongols etc etc etc. Back in the day this may have been over done, recently I have started to look at myself as it is basically all new to modern players as even FR these days is focused on the Sword Coast rather than places like Unther, Mulhorand etc.
6. The Dark Continent
This is basically fantasy Africa and it may not be to PC these days. A modern variant of this perhaps is Xendrik in Eberron which puts fantasy cultures in an African type continent. Paizo's Golarion setting also has a rough equivalent. Basically think lots of jungles, rivers and ruins, fantasy Zulu and Xhosa etc. While it may not be to PC these days you could do this in a 5E game but I would look at some real life medieval/antiquity African civilisations (Mali, Kush, Ethiopia, Great Zimbabwe, Makuria etc) to balance out the dark continent aspect of it.
7. The Jungle Ruins.
Basically a mixture of the dark continent and real life culture this is basically a fantasy jungle type land with Olmec/Azetec/Maya type civilisations. Chult in FR is a modern example which has been visited in Tomb of Annihilation. These type of adventures also turned up a bit in Dungeon magazine. Of course fantasy jungles are full of things like Yuan-Ti, dinosaurs, dragons, etc.
8. Lost World
This more or less includes things like dinosaurs and other extinct megafauna from earth. X1 The Isle of Dread is probably the most famous example of this trope. Neanderthals are often present as well, and you can place things like Rakasta/Tabaxi, lizard men and other reptilian races in these type of adventures/campaigns as well.
1. Magical Fountains
Old adventures such as B5 Horror on the Hill often have a magical fountain or water source in a forest that has a magical effect. These are often healing or random effect based with sometimes a negative effect. You might be healed, gain a boost to an ability score or be poisoned etc. I have seen things like this turn up in Castles and Crusades products and the Pathfinder Kingmaker adventure path or conversions of 3pp to 5E (Quests of Doom, Troll Lord Games C&C conversions to 5E etc).
2. Hexcrawls
Hexcrawls were not a massive part of AD&D but they did turn up in several X series of of adventures. The most famous is X1 The Isle of Dread but they also used them in Quagmire, Master of the Desert Nomads and War Rafts of Kron for example. They usually feature things like keyed locations and wandering monster tables. 5E has attempted this on a smaller scale with Princes of the Apocalypse but the 6-8 encounter expectation and overall nerfing of monsters makes it a bit harder in 5E (eg Wyverns are no longer save or die). The Stolen Lands (pt 1 Kingmaker AP Pathfinder) is another example of a hexcrawl that I think could be adapted to 5E. You would probably have to use some stronger monsters on random encounter tables and have more keyed locations (small dungeons and encounter areas) to make it work. Granting xp or milestone rewards for exploring hexes is another idea. Older hexcrawls were often an island or continent wide in scale.
3. Underwater Adventures.
Not to many published adventures are an underwater adventure module but they turn up fairly frequently in old Dungeon magazines. They are generally for level 3-6 ish PCs set before they can reliably cast water breathing spells. Often NPCs supply potions of healing. Sometimes they are combined with a hexcrawl and something like an undersea boat or other submersible is provided. The War Rafts of Kron is set mostly underwater that allows you to explore the bottom of the Sea of Dread and is a higher level adventure (9-12). Its also interesting to see how they structured encounters back then to challenge high level PCs. An encounter with 4 Triton wizards each packing lighting bolt riding giant sea horses is an interesting idea IMHO.
4. Environment Adventures.
Remember Sandstorm and Frostburn books in 3.5? They were nothing new with old adventures such as B4 The Lost City, Pharaoh, Desert of Desolation series featuring deserts while arctic adventures often cropped up in Dungeon magazine. Darksun is also this idea turned up to 10. For whatever reason deserts seem more popular than arctic adventures probably because there are numerous examples of ruins in places like Egypt, Iraq, Syria, Tunis etc.
5. Real Life Cultures
This is generally fantasy versions of Egypt, Rome, Greece, Aztecs, Olmecs, China and Japan. The Realms have several of these tropes along with Golarion and the Kobolds Midguard and Southland settings. The poster child for this however is Mystara/The Known World which has fantasy Romans, Egyptians, Greeks, France, Italian city states, Arabs, Vikings, Mongols etc etc etc. Back in the day this may have been over done, recently I have started to look at myself as it is basically all new to modern players as even FR these days is focused on the Sword Coast rather than places like Unther, Mulhorand etc.
6. The Dark Continent
This is basically fantasy Africa and it may not be to PC these days. A modern variant of this perhaps is Xendrik in Eberron which puts fantasy cultures in an African type continent. Paizo's Golarion setting also has a rough equivalent. Basically think lots of jungles, rivers and ruins, fantasy Zulu and Xhosa etc. While it may not be to PC these days you could do this in a 5E game but I would look at some real life medieval/antiquity African civilisations (Mali, Kush, Ethiopia, Great Zimbabwe, Makuria etc) to balance out the dark continent aspect of it.
7. The Jungle Ruins.
Basically a mixture of the dark continent and real life culture this is basically a fantasy jungle type land with Olmec/Azetec/Maya type civilisations. Chult in FR is a modern example which has been visited in Tomb of Annihilation. These type of adventures also turned up a bit in Dungeon magazine. Of course fantasy jungles are full of things like Yuan-Ti, dinosaurs, dragons, etc.
8. Lost World
This more or less includes things like dinosaurs and other extinct megafauna from earth. X1 The Isle of Dread is probably the most famous example of this trope. Neanderthals are often present as well, and you can place things like Rakasta/Tabaxi, lizard men and other reptilian races in these type of adventures/campaigns as well.