D&D General How much time exploring a 6 mile hex?

We're about to start Isle of Dread and one of the adventure hooks I have is filling out the unexplored area of Rory Barbarossa's map*. I'm unsure how long it would take for an adventuring group to properly explore a six mile hex in order for a cartographer to say "yep, definitely mark a little palm tree in that hex. It's all jungle here." I guess that simply moving from one side of the hex to the other side would not be enough (maybe I'm wrong though). So I need a base time of exploration as a point of reference.Then I can add in circumstantial factors like "is the party moving slowly and carefully" or "is there a ranger in the group."

*Rory Barbarossa's map
x1-isle-of-dread-6-pc-1981.png
 

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iserith

Magic Wordsmith
It really depends on what you're trying to incentivize in terms of the adventure in my view. If the premise was to map out the island, I would tie XP to mapping out a hex. Then I would make that reasonably difficult to do.

For example, the PCs must travel 3 miles per side of the hex that does not border a hex they already mapped plus, say, 6 miles on top of that. So a given hex might be 6 to 24 miles of travel to fully explore and map it. At a normal pace (by D&D 5e rules) that means 2 hours to 1 day of travel. If the PCs move faster, they get it done faster, but suffer a -5 to PP and can't engage in certain travel tasks. If they move slower, they get it done slower, but can engage in more tasks plus be stealthy. Tie random encounters to time (maybe 1 check per 4-hour "watch") and the ability to map to weather which you roll for daily (no mapping in the rain). When they map a hex successfully, reveal the terrain and award XP.
 


Endroren

Explorer
Publisher
There are some real world references you can use. It is estimated that Lewis & Clark covered roughly 10 miles per day. (https://www.washingtonhistory.org/wp-content/uploads/2020/04/MathOfThePath.pdf) Sometimes more, sometimes less, depending on their mode of transport. Considering mapping was an important part of their mission, that's probably a good starting point. Adventurers aren't necessarily experienced surveyors, but you could argue that the Ranger makes up for that. For a full survey of the hex, rather than a straight line survey, I'd suggest it'd take a day to perform a full survey of a 6-mile hex. And I agree with others that Survival checks would be in order, especially for spotting important locations and points of interest.
 

J.Quondam

CR 1/8
If the goal is to create a map, then (in some places) the PCs could probably also get away with using a spyglass from high ground to spend a day or so roughly mapping out adjacent hexes, weather permitting. That would be a little more efficient for them, and could even help them spot ruins, etc, for a closer look (ie, give them advantage/bonus when it comes time to really exploring that hex).
 

to properly explore a six mile hex in order for a cartographer to say
Depends what you mean by this. To make a map at a 6 mile resolution, all you need to do is walk through it. But to determine if anything "of significance" is actually in that area? A day. If there is something of interest, it could be found immediately, or at the end.

Things like springs, small lakes, buildings, etc are going to be missed in things like a jungle or forest at distances of a half mile or even less.

More importantly, how do you want the game play to go? Reward what you want, and don't worry about too much realism.
 

As a straight realistic answer:

A 6 mile hex (measured side to side, or center point to next nearest center point) is about 31 square miles. The island here is about 24 hexes tall by about 16 hexes wide, plus some peninsulas, so say 400 hexes. 400 hexes is 12,400 square miles of land area. That would make it the 42nd largest state in the US by land area, ahead of Rhode Island, Delaware, Connecticut, New Jersey, New Hampshire, Vermont, Massachusetts, Hawaii, and Maryland. It's about three times the size of Puerto Rico, or 10 times the size of Long Island. It's almost exactly the same size as Taiwan, and it's bigger than Belgium and Albania.

So, it's pretty big.

Coincidentally, the city limits of my hometown is close the size of a single hex at just over 35 square miles. It's a mostly suburban small town of ~45,000 people. It includes a large industrial area, some 50 churches, a dozen hotels, several major commercial centers, two decent size rivers, several small parks, two golf courses, three large cemeteries, a landfill, a library, a museum, a botanical garden, two theatres, two large water towers, 30 or 40 different apartment complexes, etc. It's large enough to have two high schools, two middle schools, and seven elementary schools. We could close a couple of those without the county beyond the city limits, but not that many. If you were looking for something the size of a woodshed, I would imagine it would take several days to conduct a thorough search of an area the size of the entire town even if it were in it's natural state of a mix of light forest and river wetlands. Difficult terrain like mountains, heavy forest or jungle, or something similar would likely take much longer.

Travelling through a place of this size is in no way a thorough search of it. My hometown is bounded on two sides by about 12 miles of four lane limited access divided highway (i.e., an interstate) with four exits that lead to the town, and by a large you can't even see anything from that road. Neither of the two water towers in town are even visible from the highway.

However, I agree with the others that it probably depends more one what's going on.

  • What are the PCs looking for? The remains of a single lost seaman? A large structure or tree visible from miles away? If it's small, it's going to take a long time. If you can see it from several miles away, it'll be much faster.
  • Is this intended to be a brute force hex crawl? If so, I'd stick to one hex = one day.
  • Are the PCs expected to do something other than brute force the search? Do they have special resources (i.e., information that they should have, people they know they should see) that would help? In that case, setting it to one hex = 2-3 days, doubled to 4-6 days for difficult terrain might work.
  • It's also different if they can reliably fly all day, or if there's a ranger who won the favored terrain lottery. Depending on what they're looking for, that might help a lot.
 

Yora

Legend
Identifying the predominant environment type by simply passing through an area seems good enough to me. You really just want to figure out the average terrain.

But to actually find anything specific in a 6 mile hex area would take ages. Finding a house or a cave in a 6 mile hex area probably would take weeks or months. It's a massive area.
 

jgsugden

Legend
We're about to start Isle of Dread and one of the adventure hooks I have is filling out the unexplored area of Rory Barbarossa's map*. I'm unsure how long it would take for an adventuring group to properly explore a six mile hex in order for a cartographer to say "yep, definitely mark a little palm tree in that hex. It's all jungle here."
That would depend upon a lot of factors. Your visibility is going to be impacted by things that block line of sight, weather, height, etc...
I guess that simply moving from one side of the hex to the other side would not be enough (maybe I'm wrong though). So I need a base time of exploration as a point of reference.Then I can add in circumstantial factors like "is the party moving slowly and carefully" or "is there a ranger in the group."
Generally, you can see about 3 miles of flat earth around you. When things stick up out of the earth and are large, you can see them from a furthe distance. If you fly up in the air (or climb something tall), you can see farther. From 100 feet you could see 12 miles, and from 500 feet up you could see 30 miles.

If all you're trying to do is decide whether to label something as jungle, plains, water, hill, mountain or desert, you might be able to get some elevation and place those labels for many hexes around you.

However, if you want to know if there are ruins in the jungle, a village amongst the trees, etc... you likely need to be much closer.

Here are some of my basic rules for Hexploration:

1.) I use 6 mile hexes, but each hex is subdivided into 7 zones. C (center) and 1 through 6 (in clockwise order). Each subhex is roughly 2 miles across. I use these subhex notations to identify which part of a 6 mile hex things are located within when hexplored. I think of the map in 6 mile hexes, but these subhexes are used to organize the finer details, if that makes sense.

Hexagon breakdown.JPG


2.) There are four tiers of 'hex information' - Unexplored, Seen, Explored and Searched. An Unexplored hex has never been seen and it could be anything. A Seen hex has been seen from a distance, but the smaller details of the hex are unknown. You could say it is forest or that there is a large lake within it, but not know if there are ruins in the forest or a village along the lake. Explored has been seen to a level where landmarks that are not concealed are now known, and Searched is a level where you have a good chance to uncover hidden secrets like an overgrown mine shaft, a faerie ring in a dense forest, or ruins at the bottom of a lake.

3.) If the PCs move at typical speed, have access to no flight, and are dealing with easily traveled terrain, it takes 2 hours to See a hex that is relatively clear. It takes a day of adventuring to Explore a hex. It take three days to fully Search a hex. If the terrain is rough, we double that time.

4.) If they have access to elevated sight, they can see much further, potentially Seeing many hexes. From 50 feet they can see hexes around their current hex. From 125 feet they can see 2 hexes in every direction. From 250 feet 3 hexes. From 400 feet 4 hexes. From 1000 feet they can see 5 hexes. From 1500 feet 6 hexes. This often is achieved with the assistance of flying familiars, a flying PC, etc...

5.) Mountains can be seen from 8 hexes away if there is line of sight (no jungle blocking, etc...)

6.) For each thing that is available to be discovered on a map, I indicate four things: Location (Hex/Subhex), Chance detected when seen, chance detected when explored and chance detected when searched. Some thing will automatically be found when explored or searched, while there is a chance to detect it when seen. Other things have no chance to be noted when seen, a slight chance when explored, and a greater chance when searched.

7.) The chance to detect is labeled as a percentage chance, and when I roll to determine whether it will be discovered I add either 1.) The best passive perception in the party, or 2.) The result of a perception roll (which is likely at advantage due to assistance) from the party. The only ones that can participate are the ones that are looking. If the detection requires manipulation (as in the ruins are beneath something that can't be seen unless an obstruction is removed) I substitute investigation for perception.

8.) The party can split into sub groups and explore in smaller groups - but splitting the party can be dangerous. If your 6 PC party wants to explore 6 hexes in a day, they can do so ... but they may not all survive.

How does this play out in "real life"?

Usually, one PC has a way to see from a high elevation (raven or owl familiar, aarakocra, flying tiefling), so there are a lot of "seen" hexes right off the bat. This influences where they want to explore and search. My DM map of the area tracks what has been explored and seen, and I give them a separate map (consider using these: Tabletop Games | Headless Hydra Press) to show what they've seen. My map has checkboxes in each hex for seen, explored and searched.

PCs often miss things in hexes, even when searched, because they just fail the rolls. They have other ways to uncover these secrets via speaking to native creatures/beings of the area, so I let that occur naturally.

60% of my hexes are "interesting" as a general rule - enough that there is stuff to do, but not so much that PCs feel like they likely missed something if they do not find anything.
 

One addition or comment, if you go with something like 60% chance of finding something interesting when searching a hex, don't make it a one and done thing. Even when searched, it would be easy to miss something like a cave or a building or faierie ring. So each time the square is searched, allow a new role to see if something is discovered this time around. Maybe reducing the chance by 10% each time to prevent one hex from containing a thousand things and to give reason to more to the next hex.
 

pnewman

Explorer
31 square miles is about 864,230,400 square feet, or 34,569,216 five foot squares. If they take one six second turn to search each square it will take them 57,615 hours to do so. If they do so 12 hours per day and 365.25 days per year they can complete the project in about 13.145 years. If the party has five members and they all search different squares at the same time it will take only about 2.629 years. By then they'll have to start searching all over, to find everything that has changed in the last 31 months.

Therefore the search will take forever....
 

jgsugden

Legend
One addition or comment, if you go with something like 60% chance of finding something interesting when searching a hex, don't make it a one and done thing. Even when searched, it would be easy to miss something like a cave or a building or faierie ring. So each time the square is searched, allow a new role to see if something is discovered this time around. Maybe reducing the chance by 10% each time to prevent one hex from containing a thousand things and to give reason to more to the next hex.
Sure - but generally people do not search, or even explore, a hex twice. They want to move on to the next hex. Thus, if they miss it, the most ready path to 'discovering' what they miss is through social engagement, not exploration. This is not a universal rule - just a trend I see over and over.

The chances I use range wildly depending upon circumstance, and I give bonuses and penalties on the fly to adjust for circumstance. This is something that has 10,000,000 or so variables - so you need to trust in your approximation skills.
 

Yora

Legend
I find hexes much more useful as a length approximation of curvy paths rather than as a unit of space. If you're in a forest or mountain area, you won't find most interesting locations by just wandering around. First someone needs to give you a hint where something can be found, and then you can try finding it based on the clues you've been given. The hexes only tell you how long it takes to get from one known point to another.
 

31 square miles is about 864,230,400 square feet, or 34,569,216 five foot squares. If they take one six second turn to search each square it will take them 57,615 hours to do so. If they do so 12 hours per day and 365.25 days per year they can complete the project in about 13.145 years. If the party has five members and they all search different squares at the same time it will take only about 2.629 years. By then they'll have to start searching all over, to find everything that has changed in the last 31 months.

Therefore the search will take forever...
I'll have to save this for my island of sisyphus adventure
 




overgeeked

B/X Known World
We're about to start Isle of Dread and one of the adventure hooks I have is filling out the unexplored area of Rory Barbarossa's map*. I'm unsure how long it would take for an adventuring group to properly explore a six mile hex in order for a cartographer to say "yep, definitely mark a little palm tree in that hex. It's all jungle here." I guess that simply moving from one side of the hex to the other side would not be enough (maybe I'm wrong though). So I need a base time of exploration as a point of reference.Then I can add in circumstantial factors like "is the party moving slowly and carefully" or "is there a ranger in the group."

*Rory Barbarossa's map
I default to the method used in Dark of Hot Springs Island. You automatically find the one important thing when you enter the hex. It doesn't mean you're there, at that location, only that you're aware of it. Like seeing the 100' tower (which you'd actually see from about 12 miles away, but anyway) that is the main points of interest in the hex. To find anything further, you spend a 4-hour watch exploring the hex...which yields another important point of interest or secret about a previous point of interest in the hex. Dark of Hot Springs Island usually has three main points of interest in each hex. The first is automatic, the second takes a 4-hour watch to find, the third takes a 4-hour watch to find. But you could go as deep as you wanted. Going with the predominant answer so far in the thread, "one day", that would give you enough time to find four big points of interest...but not necessarily explore them all.
 

Good to know, but that's A 5th level spell. The druid wouldn't get that until 9th level. I'm fine with that
Creative use of Locate Object could be good if you allow trees as objects. It only lasts 10 minutes though but you could target a type of tree and get the general density within 1000 feet. Is water an object? I wonder how that would ping if you used that spell.(probably, OMG, THERE'S WATER EVERYWHERE!)..but you, as a DM could allow it to find nearby pools or springs.
 

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