View Full Version : DM Help Campaign Concept: Explorers and Traders of the Great River

2021-07-23, 03:53 PM
I came up with a new concept for a sandbox-type campaign earlier this week:

The setting is a great river like the Amazon, Volga, or Mississippi, with numerous branches spreading out over a vast area. In ancient times, the river has been home to many great civilizations of supernatural creatures, but they are all long gone, with the serpentmen having disappeared over a thousand years ago. The abandoned cities on the lower river where discovered and resettled by neolithic humans, and with rudimentary understanding of the languages of surviving descendants of the monster races, they discovered the technological and magical secrets to grow into an advanced Bronze Age culture of their own. But their numbers are still quite small, and their settlements mostly limited to the lowest parts of the river, with the upper branches of the river still almost entirely unmapped and unexplored. And the old ruins flanking the banks still hold many valuable treasures and unknown magical secrets.

So every year at the end of the flood season, explorers set out to go exploring up the river, to return back to the cities with their hauls several months later. Over the generations, sites of valuable natural resources have been discovered on the upper river, with various mining, logging, and hunting camps being established, followed by trade posts that serve as bases for the river merchants who deliver supplies to the workers. And of course, cargo ships going up and down the river with supplies and valuable resources attract river pirates who hide in their camps among the countless small side branches. But the further up the river one goes, the more sparse even these become until there's nothing but unexplored Wilderness ahead. And still more ruins that hold greater treasures, as well as greater and less known threats.

Characters would start at 1st level on the lower river with just their equipment and two or three canoes to see if they can find any worthwhile of scavenging still left in the ruins or make some extra coin fighting pirates or guarding merchant ships heading in the same direction. And perhaps have some small adventures in the work camps and trade posts where they can stop to resupply. As they get wealthier, they can afford larger boats with hired crews, that can pack supplies for longer journeys and carry greater amounts of heavy salvage. They might even be able to pick up some goods too trade when they still have space in their holds. When they get richer and have more money to spare, they can afford the higher prices for supplies at trade post higher up on the river instead of needing to return all the way down the great ports. If they want to, they could even establish their own permanent bases in old ruins or abandoned trade posts.

I didn't notice it at first, but this idea has many similarities with the Ultraviolet Grasslands RPG, and the style I am aiming for somewhat comparable with the Yoon-Suin setting. But the image I have in mind also takes many inspirations from Morrowind, Fallout, and Kenshi. Currently I see the civilization of the great ports to be basically Dunmer. And as can be guessed from recognizing only a few of those inspirations, I want to go really weird with this. :smallbiggrin:

There are two primary things I would like to discuss: Setting elements and game mechanics. Setting elements are basically any suggestions you might have in regards to creatures, cultures, NPCs, sites, and so on. With mechanics I mean systems to structure the game that are in addition to whatever rules such a campaign might use for character abilities and task resolutions.

I think this concept combines many elements from both hexcrawls and megadungeons. While it is superficially like a hexcrawl with limited movement options, I think the wilderness of the river can also be approached as a megadungeon that just happens to have the occasional friendly settlements in it. In this model, the river would be like the corridors and tunnels, and the various ruins and camp sites like individual rooms. I think for a campaign like this, it would probably work quite well to have individual ruins be relatively small dungeons, which the party can clear out in one game session or two. There can be the occasional bigger dungeons, but I'd keep those the exception.
And where the the structure is more like a megadungeon than a hexcrawl is that the river makes the party pass through the same areas multiple times, as they go up and down the river. Though with a river with frequent branches, they would not always go through exactly the same areas on every voyage. I think this can lead to quite interesting situations, where the players know in advance to bring two goats to threw into the water when they have to get past the lair of the giant crocodile, or make bargains with dangerous locals to let them pass through their territory. And while they will be passing through some of the same settelments many times, they might do so only two or four times per year before the flood season starts and going up the river becomes impossible for several months. A lot can change between visits, and players might find that there has been a change in leadership and they are no longer welcome in a place they used as their main base camp for the past three years.
A campaign like this should benefit hugely from a robust system for random encounters. Those can consist of dangerous creatures either in the water or prowling on one of the banks, or creatures that are hugely valuable to hunters, and of course crews of river pirates. But it can also be merchant ships that allow the players to have a one-time access to a store out in the wilderness. Or they can come upon a wrecked ship, with its crew maybe gone or still on board and in need of help. Their own boats can have an accident that needs to be dealt with, or smaller side branches can have something fallen into the water that is blocking their progress. Different branches of the river can be assigned to different encounter tables, which have their own frequencies of encounters and types of encounters. Players keeping track of their encounters and questioning knowledgeable locals can then make their own decisions which branch they would rather go explore on.
Because of that last point, I think it'd probably be a good idea to not fix the location of ruins (and perhaps even some settlements) on the map before the players either spot them, or hear about them from other explorers and locals. You could have a near infinite number of sides branches the players could go explore and it seems both crazy and unnecessary to pin certain sites to specific locations before they become relevant.

As for travel distances and times, going along rivers thankfully makes everything really easy. No need for hexes to estimate the distance between any two points. You can simply write down the distance between any two points on the river right on the map. I think it would be convenient to make a map in a way that indicates the maximum size of vessels that can navigate any stretch of water, the terrain type on the banks of the water (in case it's necessary or more convenient to walk), and also the speed of the current of the river.
From some cursory research, I found that a typical speed for a canoe is about 3 miles per hour, and that many rivers run at a speed of 1 or 2 miles per hour. That makes the calculation for speed traveling up or down the river very easy. 3 mph base speed and +/- 1 or 2 mph depending on the current. You can also have currents of 3 mph and faster, but on those rivers you'd have to march towards your destination and then build a raft for the return trip. I think the knowledge that the return trip will be much faster that the journey getting to your destination might have interesting effects on how players might approach planning for adventures.

That's what I got so far. Any kinds of suggestions how I could improve and expand on this concept, and for fun encounters or sites to put into a setting like this are greatly welcome.

Sparky McDibben
2021-07-23, 07:56 PM
This is dope as hell Especially love how much thought you've put into the megadungeon structural similarities.

What are your thoughts on stocking it with content? D&D doesn't have that many neat river monsters.

2021-07-23, 09:05 PM
This sounds like a really cool idea for a setting. What are your thoughts on the climate/terrain around the river? Is it an arid climate like the lower Volga or the Nile, or a jungle/forest like the Amazon? That's going to make a difference in how agriculture functions, how much of the basin has been explored, and how viable overland travel is. It's also going to influence what the flood regime looks like.

Something to keep in mind is that rivers are very dynamic systems. Sandbars come and go, and channels migrate both gradually and suddenly in response to floods, so even a well-traveled section of river can become hazardous and need to be mapped again after a flood. And in extreme cases, the navigable portion of the river may suddenly be ten miles away from where it was last year.

Anyway, some ideas for interesting things that could happen on a river (other than the obvious - river monsters, pirates, and the like):

A drought has left large stretches of the river impassible, stranding upriver communities. Somebody needs to scout an overland route for a caravan of supplies.
A heavy flood has reopened an old side channel, along which several previously-unknown ruins are found. A mad rush to claim them ensues.
The same flood has left a thriving town high and dry as the main channel migrated several miles away.
The land between the old and new channels is now claimed by communities on both sides of the river (https://en.wikipedia.org/wiki/Thalweg#Thalweg_principle).
Exploration of a tributary discovers a massive dam built by the ancients, and it's at risk of collapsing, unleashing a torrent that would kill thousands. Alternately, that already happened and the PCs need to deal with the aftermath and/or see what they can salvage from the former lakebed.
Plague has struck an upriver community at the height of flood season. Can anybody reach them to provide aid?
The annual floods start early, catching the PCs at their upriver camp and forcing them to head inland to reach high ground ahead of the rising water.
Bifurcations and complex drainage patterns are cool in general, though I don't have any specific ideas for plot hooks. The Casiquiare Canal (https://en.wikipedia.org/wiki/Casiquiare_canal) is a relevant example.
A significant tributary/side channel is blocked by a major landslide (https://en.wikipedia.org/wiki/Bridge_of_the_Gods_(land_bridge)).

2021-07-23, 10:05 PM
One thing of importance here is the geographic specifics of your river and whether or not it flows primarily east-west versus primarily north-south. This matters significantly in terms of the kind of environmental variation you encounter. The Amazon, for example, flows primarily east-west and encounters a fairly limited amount of environmental variation across it's course - it's basically tropical the entire way and only differs in how much vegetation, from roughly savanna to jungle, you're dealing with. The Mississippi, by contrast, ranges from subtropical environments in the lower reaches, to a highly seasonal continental climate in the upper regions and ranges from thick temperate forest in the eastern watershed to desert in the western parts. So it depends on how much variation you want and how punishing you want environmental factors to be - ex. characters adventuring on the not-Amazon don't really need to worry about bringing winter clothes, while those on the not-Mississippi absolutely do.

2021-07-23, 11:41 PM
This is a sort of exploration game I would love to play. The first thing I thought about is what is the source of the main river? Magical, massive mountain, endless lake, the ocean, or itself as it is actually a world traversing river?

River monsters aren't the only thing to worry about. Out in the wilds there could be ANYTHING. From sci-fi aliens and space ships to giant mutated 3 headed bears. What really caused the fall of civilization?

2021-07-24, 07:36 AM
Here is the general layout simplified to a Melan diagram that I have in mind.


Green markers are "civilized cities".
Red markers are "frontier towns/trade posts
Brown markers are "possibly friendly locals"

Starting from the cities, the South Branch has a length of 1400 miles, the West Branch a length of 1600 miles, and the East Branch a length of 1800 miles.

I had considered turning my old setting into two separate river systems, but I think as a new setting from the ground up, having the whole setting be just a single river makes more sense. I've been thinking that the Black River and the Green River are being separated by a mountain range running between them. The cities have a Mediterranean climate, with the Green River north of the mountains being temperate, and the Black River in the south being sub-tropical. With almost all of the land being highly forested.
There's not really any good analogous places of Earth that would work as a comparison. But after some consideration, I think I want to have the Black River take environmental inspirations from Northern India, and the Green River have an environment like Oregon, Washington, and Idaho, though with a lower gradient of inclination going east. (While the major rivers in the region all look quite big, they are all extensively dammed to artificially raise the water to this level, specifically to make them accessible for larger ships.)
Unlike shown on the diagram, the Green River might actually go pretty far north, and beyond its source there could easily be a huge continental landmass that reaches to the arctic. So summers on the East Branch can still be quite toasty, while the winters would be unimaginably cold for people from the lower river. I think in a realistic climate model, you'd end up with arid regions somewhere in the river basin and the flood seasons for the Black and Green River would be a completely different times, but since I want to go with a very weird fantastical world, I think this is something that can be glossed over.

I had been thinking to let the sources of the main river branches remain an eternal mystery that humans can never discover. But finding the sources and discovering them to be something amazingly strange and fantastical could actually make really cool endgame adventures for high level characters. They could be the first people to ever get there, and when they get back nobody would believe their strange tales. I agree that there should be something amazing, but I think that's something that could be left to get further developed if a party of adventurers actually starts having a shot at getting there. I quite like the feeling that the river could just go on forever.
After all, it would be 1800 miles to reach the source of the Eastern Green River. At an average speed of 30 miles per day, that's 120 days of paddling for the whole round trip. Plus days spend resting and exploring stuff along the river banks. And the players might even want to establish several supply depots along the route because they can't carry everything they need for a 4-6 month expedition at once.

There's a lot of cool things you can do by having an adventuring season and an off season (http://udan-adan.blogspot.com/2017/01/the-long-haul-time-and-distance-in-d.html). One idea I am toying with is to make a couple of rolls at the end of each flood season to see how things have changed. Is the water level low this adventure season and some branches are not passable for larger ships? Or is the river unusually high and larger ships can go into branches that are usually closed to them? Have any settlements been destroyed by flooding and which ones? Have there been landslides that make new ruins visible from the river? Realistically, high water wouldn't remain high for the whole year like low water can, but I think that's a degree of detail that could be ignored.

You could also do a roll at the start of the season to check for a flash flood. Roll a d12 to determine the month. A 1 to 8 indicates the month of the adventuring season, and a 9 to 12 means there's no surprise flood that year. Then roll 1d20+1d10 (or a d30 if you are one of those funky dice people) to determine the day. Wherever the players happen to be on that day, they'll have to deal with a very sudden flood.

2021-07-24, 09:15 AM
The Mississippi, by contrast, ranges from subtropical environments in the lower reaches, to a highly seasonal continental climate in the upper regions and ranges from thick temperate forest in the eastern watershed to desert in the western parts. So it depends on how much variation you want and how punishing you want environmental factors to be - ex. characters adventuring on the not-Amazon don't really need to worry about bringing winter clothes, while those on the not-Mississippi absolutely do.

I think the Mississippi makes for a great source of inspiration. Just look at all the biomes this monster spans:


2021-07-24, 10:13 AM
One cool option with a river of this size is that you can have smaller side branches with magically toxic water that affect only that particular branch. Once they flow into one of the major river, the toxic water becomes dilute to the point that it's harmless.

I spend much of the day developing a system for mapping a river as a pointcrawl. Similar to a regular river diagram, and not much different from the map in UVG, but with a couple neat features.


It's a different presentation of exactly the same river as in the diagram I posted earlier using the same colors (cropped down so it doesn't show all five pages).

At the side of each section, there's a River Rating. The letter tells you if you can enter that section of river with your ship, and the number tells you how many miles per hour you have to add or subtract from your ship's speed when you enter it. This presentation looks usable enough with only three main branches at any part of the river. For smaller side branches, you have to make a new map of the same type, which then can also have steps of 1 mile instead of 10. (Or whatever you want to use.) The starts of new branches can then be written into fields on on the main map.

Sparky McDibben
2021-07-24, 12:09 PM
I can't see your map, but I am FASCINATED by this description. Can you post your full pointcrawling structure?

2021-07-24, 02:29 PM
Here is the basic, and still untested procedure I have in mind:

Adventuring Seasons
The campaign uses a calendar on which the current day is always tracked precisely. A year begins with the start of the Adventuring Season, which goes for 8 months and is followed by a 4 month off season in which long-distance travel is impossible, but town adventures could happen around the PCs home base.

At the start of each adventuring season, a d6 is rolled to check whether the water level of the river is unusually high or low this year. A roll of 1 means low water levels, a roll of 6 high water levels. The river map indicates the maximum size category for ships for each section of river. Category A is accessible to ships of all sizes, and category D only to the smallest canoes and rafts. Category X can not be used by any boats. In years of high water, sections of river can be used by ships one size larger than normal, in years of low water only by ships one category smaller than normal.

When the party reaches a settlement on the river for the first time in a new adventuring season, a d12 is rolled to check if any disastrous event has affected the settlement during the off season. A roll of 1 indicates that it was destroyed or damaged by a flood, attack by pirates, outbreak of disease, or some other kind of calamity. One could make another random table to specify the type of the disaster, but I'm probably gonna pick something that seems appropriate myself. It's probably smart to make the check once the players decide they will travel past a settlement and not wait until the moment they actually get there.

The Map/Chart
The primary map to track progress is a long chart that shows the main courses of the river with a space to note a specific site every 10 miles, including forks in the river. Smaller side branches forking off from the main course can have their own detailed charts. Players could go exploring side branches blindly and see if they discover anything interesting at random, but I think in the early parts of the campaign when they still stick to the lower river that has already been somewhat explored, they can find or buy maps that show how to get to ruins in the forest that other explorers have seen through the trees and still might have interesting things in them to find.
The further they travel up the river, the more ruins there are close to the main courses that have not been explored by anyone yet, and the players can simply head out up the river to see if they spot anything they want to check out.

Travel Distance and Time
In a pointcrawl, it's pretty easy to track progress along the routes in miles and miles per hour. When traveling on foot along the river banks deeper into the forest, use whatever mechanic the game system used for the campaign uses. For travel on water, I found the following speeds to be reasonably realistic: Canoe 3 mph, dhow 8mph, junk 4 mph, galley 6 mph. For other ship types, research their typical speeds. (At low speeds like these, knots is pretty similar to miles per hour.)
My river charts show the speed by which the water in a section of river usually flows. When taking a boat going up the river, that speed has to be subtracted from the default speed of the boat. When going down the river, it is added to the speed of the boat to get the actual speed. Usually, parties can travel on water for 10 hours per day. (Though I guess on larger river sections, bigger ships on which characters can take turn steering while others sleep could also travel through the night if there is good moonlight.) Going for 10 hours in a 3 mph boat against a 1 mph current means the party travels 20 miles that day.

All characters have to drink one ration of water and eat one ration of food every day. Being on an unpolluted river with no large scale fishing, getting new water and food at any time should not be an issue, but supplies should still be tracked in case the party ends up going deep into a large dungeon or explores river branches with bad water. Different games have different mechanics how to deal with lack of food and water. (Though I think Worlds Without Number has a particularly good one.)

When going into the wilderness on foot or in small canoes, the weight of supplies for long journey becomes important. Counting the specific weight of all items characters carry is usually impractically fiddly, so it's generally a good idea to somewhat abstract it with an encumbrance system that only tracks the number of items carried by a character or loaded into a boat. (Again, WWN has a great system for this. The game is free for download.)

A simple rule I came up with to collect arrows after a fight is to roll 1d10 for every character who used bow and arrow during the fight. That number determines the amount of arrows the party recovers. (Some might have dropped to the ground after missing, some stick in corpses, and others are still in the quivers of defeated enemies.) Much easier than counting how many arrows all enemies had at the start of the fight and how many arrows where shot and whether they hit or missed.)
Alternatively, characters in a Bronze Age setting might probably know how to make stone arrows that deal 1d4 damage instead of 1d6.

The Adventuring Day
When in the wilderness, the party makes four checks for random encounters every day. Three checks during the day and one check at night. In sections of the river with many travelers and creatures, the roll is made on a d6, while in more desolate areas it's made with a d10, though in particularly dangerous or desolate sections it could even be a d4 or a d12. Regardless of which die is used, an encounter happens on a roll of 1.
(4 rolls on a d4 per day results in a chance of 4/4, which is 1 encounter on average. 4 rolls on a d12 per day results in a chance of 4/12, or 0.33 encounters per day.)
Different sections of the river should have different tables for what can be encountered. They should include river creatures and flying creatures, and also some land creatures, which could sneak up on the party when they make camp on the shore at night. The tables should also include encounters with river pirates, river merchants, and other parties of explorers. Other great ideas to add to the encounter tables can be various kinds of accident, like a boat tipping over or getting stuck, or a sudden storm or flood. (There would need to be rules for what the characters can do to deal with these calamities.)

When rolling a random encounter with creatures or people, and the situation does not have just a single possible response towards the party, it should be followed by a Reaction Roll. A reaction roll is made on a d12. If a PC spots the creatures or people first and can try to greet them, the character's Charisma modifier is added to the check.
On a result of 2, the creatures immediately try to attack.
On a 3 to 5 they see the party as enemies or a threat, but the players might be able to avoid stating a fight.
On a 6 to 8, the creatures wait and observe how the characters react to them before they decide what to do, and may make another reaction roll the next round.
On a 9 to 11, the creatures don't want any trouble and get out of the party's way. NPCs will be willing to listen if the players want to make any offers.
On a 12, the creatures are happy to see the PCs and want to befriend them.
More than ever, the No Stupid Rule applies. If something is rolled that makes absolutely no sense, ignore the result.

At the end of the day, characters make camp for the night. They need to subtract one water and one food ration from their supplies if they can't drink from the river and try catching some fish while they camp. If they don't have food and water or can't find a dry place to sleep, they can not gain the benefits of resting during the night. (As mentioned, WWN has cool rules for that.)

When the PCs start out by themselves with just two or three small canoes, they can take care of their boats and all their supplies themselves. If they later upgrade to a larger dhow or junk, they will probably need to hire a crew that takes care of the ship and guards it while they travel into the forest to explore old ruins. They could hire these sailors either for a single journey and pay them by the day, or hire them for an entire year. If the river allows work for sailors only for 8 out of 12 months per year, their wage could be increased by +50% to allow them get through the off season.

Along the river are several settlements and trade posts where parties can buy supplies and sell treasure, and they might also encounter the ships of traveling merchants making the rounds between the river settlements. The further away from civilization the party goes, the more limited the goods for sale are, and the worse the prices get that traders are offering. Returning all the way back to the city should give them the best prices, but takes up a lot of time the players might not want to waste. Maybe it makes sense to have four to six different price tables for common items that are used in different places, depending on how far away from civilization they are?

Experience Points
Good question. I think I want to go with giving characters 1 XP for each gp of treasure they have found once they make it to a safe settlement or trade post. Treasure that is left behind or lost while they try to get back to a settlement does not count towards XP. Reward money that is paid for rescuing or capturing NPCs also counts as treasure that adds to XP. (A prisoner is effectively treasure that can be exchanged to coins.)
But I think I also want to reward making discoveries. Discovering a ruin that is not yet on the public explorer maps should give them some XP. "Sufficiently exploring" the interior of a ruin should also give them XP (regardless of whether it was on the map before or not), but defining when a site counts as explored seems difficult.

Generating adventure sites
The chart of the main courses is designed in a way to easily add in forks leading to smaller side branches. These side branches can be little self-contained sanboxes in themselves, or could even have further side branches splitting off of them. With a great deal of emphasis being on random encounters while traveling the river, ruin sites don't need to be very close and can just be a Five Room Dungeon or One Page Dungeon. Most old AD&D and B/X modules should work as larger adventure sites as well.
In addition to that, there's a great book with random tables to quickly generate a small dungeon or village with something interesting going on. That is again Worlds Without Number, which is specifically made for this kind of adventuring.

2021-07-24, 05:11 PM
Before we get technical, I would say you need to have a long think on the following:

1) Which is it really, Traders or Explorers? It’s not impossible to do both, but your mechanical decisions are going to weight one of them. If you call it T&E, but the way to wealth is to hex crawl forward into increasingly hard dungeons that generate geometrically increasing wealth and power…well, it’s going to be heavy explore, or possibly just turn into D&D hex crawl. To a certain degree a focus on Trading is going to mean keeping the players a containable power levels…stolen goods are all net profit after all…

2) Granularity and Sweep/Feel. The mechanics for a Firefly-esque struggling to keep the ship afloat or a pelt trader at the outpost versus a Rogue Trader or Renaissance merchant republic are going to feel different. Is the game about making big sweeping plays ala Billions where the wealth is vast enough that it doesn’t need to be tracked in the reaches for the story, or is it about buying a pallet of glass beads for 10 coins and selling it for 15 where every piece of overhead, every day of rations, these are things that matter.

3) Violence. How prevalent? Are you Kurtz/the Conquistadors, a French fur trapper who really can’t afford to get in to it in most cases, or a sort of Viking raid/trade on a case by case basis? Does the world support that?

2021-07-25, 11:38 AM
I think trade will likely remain a side gig to just make a bit more money when returning home after an expedition with free hold space. While I intend to give XP for treasure, I'm probably not give XP for trading profit. That's just extra cash in the bank.

I made a new version of the map that should give a better impression of how the whole thing will look like.


The first eyeballed attempt turned out to line up with the distances I had planned to within 10 miles, so the main courses are pretty much finalized. For reference, I used a 50% scale map of the Mississippi as the main structure, so this thing is big.

Green dots are cities, and orange dots are trade posts. The last trade post is at 650 miles from the sea.

2021-07-26, 05:14 AM
I really like the concept, but what reasons exist that make overland travel unviable? Is it just that river travel is faster and more efficient?

2021-07-26, 07:59 AM
What kind of actual game operating system will this have? Ie. What rules are you using for classes ? Being advanced Bronze age I am thinking Classical Greek, Hittite and Egyptian levels of tech and classes which doesn't meld well with the imagery of the 5E standard. This would work great in 2E where every class wasn't intrinsically somehow linked with magic. What races are present for players and the environment as a whole? In such a primitive world, I don't think you would see a lot of racial mixing outside the ports of the big trading cities and given the nature of such societies "They look different than us" would likely be a bigger deal than it has been in the last couple hundred years.

2021-07-26, 08:39 AM
I really like the concept, but what reasons exist that make overland travel unviable? Is it just that river travel is faster and more efficient?

Where rivers are navigable, that’s a pretty compelling reason. It’s not an accident that most of the world’s major cities are on navigable water. Compared to river travel, overland travel is almost ridiculously slow and expensive. And it requires a major investment to build and maintain halfway decent roads through dense forest and wetlands in the first place. You’d also need a ferry at any significant tributary or side channel along the way.

I suppose if you didn’t have a boat and couldn’t afford passage you could walk on the riverbank and/or on game trails through the forest, but that would be slow and arduous compared to even a canoe and you’d be more limited in how much you could bring with you. And you’d still be limited to the dry season unless you could get up off the floodplain and didn’t need to cross any tributaries. Seems like it shouldn’t be anybody’s first choice for how to travel more than a few miles.

Yora, the setting and mechanics seem very well thought out to me. Is there anything in particular you’re looking for feedback on?

2021-07-26, 09:36 AM
I am feeling very good about the stuctures and mechanics that I have put together at this point. It doesn't really require coming up with anything new that wasn't already in in the little D&D Expert Rules 40 years ago, and Worlds Without Number is an excellent resource for quickly putting together little dungeons or groups of town NPCs that may be used for just one or two sessions.
If anything, reducing the wilderness from a hex-map to a simple upside-down flowchart actually makes everything a lot easier by having all areas clearly compartmentalized. If players end up getting completely stuck with no idea how to proceed, they can always fall back to "let's get back into the boat and head further upstream to see what we run into". Since there's only the two option of continuing the stream they are on, or going back to the previous fork and taking the other stream, things become very predictable for the GM which reduces the pressure of having content ready
This also should work fantastically well for a West Marches campaign. Players can easily form a new party at one of the many trade posts, and even if nobody happens to have a ship, they can always just grab two cheap canoes and are ready to go. And they can all contribute to expanding the big master map at the Last Outpost.

I think the main thing from this point on would be ideas for ruins and encounters that incorporate the river element. Though it takes only a one minute walk away from the bank to place down pretty much any adventure you could think of. Another point to expand on is how the culture of the local population could be flavored to reference it being a river society.
For example, instead of trade caravan, there are river merchants who are going up and down the river visiting towns and villages and provide mobile supply stores for parties in areas with river traffic. Miners and loggers ferry their resources to markets at the coast on big barges, which they then tow back to port with huge long-legged river crabs.
Making rice the main crops fits perfectly, and I am thinking of putting together a simple list of main fish and water birds that are commonly eaten. Maybe have explorers wear raincoats made from crocodile skins. I think there's a whole world of elements that usually don't get looked into much in most Medieval Western Europe style fantasy settings.

Being advanced Bronze age I am thinking Classical Greek, Hittite and Egyptian levels of tech and classes.
Yes, that type of stuff.

I'm going with the Worlds Without Number system, which is a quite extensively modified version of Basic/Expert D&D. Basically it comes down to Fighter/Thief/Wizard (with priests in the form of dual-class wizard/healers).

There isn't really that much to it applying it to various types of societies. No two-handed swords and crossbows and being selective about the armor types is really all I've done in that regard. Conveniently the system doesn't bother with race abilities and modifiers for PCs, but the main culture for the cities and rice fields near the coast is based very heavily on the Dunmer from Morrowind. The other three peoples were represented in my last D&D campaign as wood elves, goliaths, and tritons. The latter obviously having a huge advantage in water, but deeper rivers are often so murky they'll still be effectively blind.

2021-07-26, 10:27 AM
On the topic of logging, you might look into the history of logging and log drives in Maine (probably other places, but that’s what I’m most familiar with) up through the early 1800s or so for ideas on what it looks like to get big trees out of the wilderness on rivers without motorized equipment. Log drives on tributaries during the flood season would make sense and be cool, with the logs being either rafted up or loaded on barges once they make it to the main channel.

Along those lines, you should stick a hill giant Paul Bunyan expy in there somewhere.

More generally, I think you can do a lot with the way river channels change course and seasonal variations in water level. The floodplain of a major river might be hundreds of miles wide, and over time the main channel migrates throughout pretty much that whole width. It’ll play with players’ expectations if they walk away from the river for two days, then find ruins that were clearly built on the riverbank.

Same thing with side channels and distributaries. Within the floodplain there could easily be islands fifty miles across and navigable channels on both sides, and it’s not impossible that you could travel up a “tributary” for a week only to rejoin the main channel. And you’d have oxbow lakes dozens of miles long. Features like that could help drive home the scale of the river, I think.

2021-07-26, 12:52 PM
One thing you'll need to think about is what races are available as PC races.

If the adventuring season is determined by Floods, then any water-breathing or amphibious species are going to have a big advantage.

One thing I had a lot of success with, as far as running a campaign that had distinct 'Adventuring' vs "non-Adventuring" sidequests was to have an abstracted, simplified "Downtime Resource" to make doing Downtime Stuff achievable.

In my campaign, the PC's were a noble house, so counting coins wasn't really a thing for them. Instead, when they got a treasure haul, they'd get a Downtime Resource, representing a large pile of money, and each Downtime I'd present them with a shopping list of things they could spend it on (One Resources could raise another unit of soldiers for their army, or upgrade their castle, fund research, buy gifts for their neighbors, or redistribute among the peasants to keep them happy).

I'd also present each PC with a personalized list of Downtime Activities for "What is your character doing during this downtime" that could affect the game.

Something similar might be useful to represent what your PCs are doing during the Flood Seasons.

As for generating Adventures, robbing from my current campaign, Theming is useful.

Come up with a handful of "Themes" representing the different types of dangers along the River.

Dangerous Wildlife

River Pirates

Undead from Ancient Civilizations

Elemental Cultists

The Evil Empire That Wants To Dominate The River.

And you can use this to guide the development of adventures. A given branch with anything worth adventuring in will fall into one of these general categories, and the challenges and type of adventures there will depend heavily on who or what is in that branch. These are the reasons why Adventurers need to go in, vs just, like, people walking in and picking stuff up.

Dangerous Wildlife might mean a pod of Dire Hippos has move into the branch, and an adventure there is either a Hunt, or trying to sneak past the animals to get your hands on whatever treasures they happen to be accidentally guarding.

Meanwhile, River Pirates are likely sending out raiding parties, and may have already found (Or brought) whatever treasures are available, so you're taking the treasures from them.
The Evil Empire isn't just seeking treasure, they're trying to establish footholds along the river and expand their control, a successful Adventure against the Empire means not just getting in and getting out, but stopping whatever their long-term plans are.

That way you can provide a bit more guidance/theme than "There's a river branch, and I guess some monsters are in there, and there's probably some treasure in there as well".

You can structure your Random Encounter system around this as well. A branch controlled by the Empire is more likely to contain Merchants, so long as you're not obviously Here To Cause Trouble For The Empire, they'll trade with you. Traveling overland is going to be more a matter of keeping your head down so you don't get captured and press-ganged than running out of supplies.
Meanwhile, an area full of Undead, the armies of a dead civilization rising to protect it's secrets, you're not likely to find friendly Merchants, although you may encounter fellow treasure hunters.

you can also use this as a guideline for building specific Threats that the PC's can encounter over and over, rather than being a one-and-done situation, a Threat can expand and evolve during the Flood Seasons. For example (This was just thrown together)

Threat Type: River Pirate
Goals: Accumulate wealth and magic artifacts
Unique Assets: Enchanted Items and Pirate Hordes

The Prince in Purple is a mage who has gathered a powerful pirate fleet under his command. Vain and selfish, he styles himself as the founder of a new Great River Civilization. He and his captains dress in expensive Purple fabrics, and put on the heirs of nobility and power. Raiding parties take wealth and slaves, all in the name of constructing the Prince's "Kingdom".

The Prince's ships are crewed by the same motley mix of Pirates that you can find anywhere, but his Captains are chosen and trained in magic by the Prince himself. In addition, the Prince's arcane shipwrights know the secret of imbuing spellwork into the wood of the ships, allowing the ships to conjure banks of fog, or sail against the current for brief periods without issue. The Prince seeks wealth and power, but most notably he seeks any new arcane knowledge to add to his arsenal.

Adventure Hooks:
The Prince in Purple has found some natural resource to exploit, and his Captains are going on slave-raids to find workers.

The Prince in Purple has heard that some ancient ruin may contain lost arcane knowledge. His Captains are rushing there to search the place.

The Prince has decided to build a Stronghold along some river branch.

If the Prince is present in a campaign, roll on the following table for each Flood season. If the Prince succeeded at some venture last season, roll twice and take highest

1-10) There are no new developments
11-13) The Prince has recruited another band of Pirates to his cause, and sent them out to prove themselves.
14-16) A terrifying new Captain has risen through the Ranks and been trained by the Prince. This is their first Raiding Season, and so they're going after a big prize.
17-18) The Prince has constructed a new fleet of Spellships, even their common pirates are seen piloting these fearsome vessels.
19) The Prince has discovered some lost fragment of arcane knowledge, and is personally plowing the river in his flagship.
20) A major town or settlement has surrendered to the Prince in Purple.

2021-07-27, 09:55 PM
One small point which may be helpful. The main current speed would be measured in the "main channel" area which tends to run close to the outside of bends. It will be slower or even run backward around the edges. So reasonably skilled riverfolk won't be have the full effect of current against them on upstream legs

2021-08-04, 06:38 AM
This is highly cool, and I’m very excited to keep up with this thread as it progresses.

I’ve been working on a water-faring campaign concept myself, but one based on the North Carolina Outer Banks. They’re a part of the world I’ve never been to, but they feature heavily in the film Peanut Butter Falcon. Watching the film, I found myself absolutely struck by how beautifully strange the landscapes were. If you’re looking for river/shallows/barge-travel inspiration, I highly recommend checking out it out. There are parts of the Outer Banks that look positively… diluvian.

2021-08-04, 01:35 PM
I decided to construct the sandbox specifically designed for a West Marches game. That means a large pool of PCs that band together into temporary parties to go on short adventures to a single site and then return to a safe port to get their rewards counted. Players can have multiple PCs so that some can play more frequently than other players in their current parties, or provide a different role in a party when their other characters would duplicate the abilities of other party members. It could also be quite easily be expanded to multiple GMs, as the focus is on having fun facing and overcoming obstacles in the way to treasure rather than any story happening in the world that the PCs participate in.

Since I am going to go with Worlds Without Number, I think its reputation mechanic is a good way to give extra awards to players who write small records of their adventures that the other players can read. That represents their characters sharing tales of their adventures with other adventurers in the area. Not only does it make them more well known, it also shares useful information on what other parties going to the same areas can expect to face. It should contribute to players engaging with the campaign beyond play time, and with the information being useful to other PCs also help players paying attention to what other players are doing that they have not gone with on adventures before.
Reputation seems the perfect mechanic for this, which fits even better than an experience bonus.
I am also thinking about creating a mechanic to let players attempt to make and read maps to find more well hidden places that can't be reached by sticking to known landmarks. That would be tied to a navigation skill, and I think it would be fun to have players pay more money for maps made by certain PCs because those are known to make the best maps. But not entirely sure how to approach that yet.

After some tinkering with it, I did find a place where this would actually fit into my existing setting, and I've been having a lot of fun ideas to make the world more strange-exotic and just a little bit bonkers. Stuff like giant hippos and dire loons, undead wastelands, and more serpentmen goodness. The setting has three main human-elf-ish people, and two more which I represented as goliaths and tritons in my last D&D 5th edition game, as they are pretty much the same archetype.
The ancient civilizations that previously inhabited the region were serpentmen, asura, fauns, and oni, who all have their distinctive architectures and lingering threats that haunt their ruins. I also plan to make the lands around the river dominated by jungles, swamps, and giant mushroom forests swarming and crawling with giant insects and dinosaurs. The river near the starting town is mostly rice fields, but a week up the river it turns into mostly wilderness with the occasional save ports with fortifications and merchants that serve as base camps for adventures in the middle river.
The upper rivers are completely uninhabited (at least by mortals), and will require different approaches by higher level parties, who will need to bring everything they will need for several months instead of just a week or two. I think it remains to be seen how well that would work once any players start being powerful and well prepared enough to even get that far. Should it turn out not working so well, there's always more smaller branches on the middle river to explore. My idea is to have the only form of power balancing being a general tendency for more dangerous creatures and bigger treasures being more common in the more distant areas. It would still be entirely up to the players to decide how far and how fast they want to push, and whether lower level characters would risk going on adventures with higher level parties planning to go on long expeditions.
The Worlds Without Number XP system doesn't seem very useful for that purpose, but the original B/X system should work perfectly. With XP requirements doubling for each level, higher level characters sticking to the less dangerous areas will find themselves making almost no progress, so I don't see that being a point for potential issues.