I have figured out how to explore unknown sea regions, but I can't figure out how to reveal unknown land.
- I am playing as France in 1513.
- I only have territory in continental Europe (but Connacht is my vassal)
- Norway owns Iceland and gave me fleet basing rights
- I finished most of the Exploration Ideas branch
- I have an explorer assigned to a fleet of 3 barques, his skills are 2/0/0/0
- I have a conquistador assigned to an army of 5 cannon, 3 infantry and 2 cavalry, his skills are 3/2/1/1
- I explored the sea part of the North American coast starting from Canada down to the Mexican Gulf
Now I want to land some troops and explore the land, because all of it shows up as terra incognita, but I can't for the life of me figure out how.
The wiki says:
A fleet led by an explorer can move into terra incognita sea provinces and thus discover them. Upon entering a sea province they also have a chance to discover neighboring coastal provinces
So I tried setting my fleet of 3 barques on patrol along the Denmark Strait, Eastern Coast of Greenland and Greenland Tip (then return to Iceland Port for repairs). But after a year or two of doing this, I haven't revealed any Greenland land territories.
I also made about 5-6 trips all the way down to Florida and back to Iceland, but that has also revealed nothing.
Incidentally, I don't see my explorer ever revealing adjacent sea regions either.
I tried loading up my 10-strong army into a fleet of cogs and sending them to Greenland, but they wouldn't unload. When I select the army and mouse over what should be the southern part of Greenland, I get the "move" cursor (ie. the green arrow as opposed to red cross you get for impassable spots) but when I right click nothing happens, they don't actually disembark. I guess "amphibious exploration" isn't possible? Granted, my cog fleet didn't have an explorer, but the army did have a conquistador.
If I use the colonial map mode, it highlights some provinces red if they cannot be colonized (there are plenty of revealed areas in Africa where I can actually click on the colony regions and check). Even though I can't actually click on any land province in the New World (it says "Terra Incognita" and doesn't allow me to select it) I can still see slivers of it at the edge of the fog. In some cases I can see colored provinces that should be native nations, and for Greenland I can actually see that the Western coast is shaded red for out of range, but the Eastern coast is not — so I would be able to even colonize it, if only I could reveal the fog. Edit: It turns out that Greenland is a Wasteland except for one single province on the west coast, so revealing it makes little difference.
In another part of the wiki, I read:
How to colonize and why?
(…)
Explorers sometimes remove terra incognita from provinces adjacent to any sea region they enter. Likewise Conquistadors can discover sea regions adjacent to the land provinces they enter.
So I understand that it's a matter of chance, and basically you keep moving to the coastal water until you get lucky and reveal the land (which is presumably the logic behind patrolling). But what is this chance, exactly? Is it something very low, like 0.1%, and I should expect to wait a long time? Or is it supposed to be something high enough that if I don't reveal after a few attempts it means I'm not doing something right?
Lastly, yet another thing I saw on the wiki:
A fleet with at least 3 light ships, or at least 3 heavy ships (Though the tool-tip says 3 light ships and 3 heavy ships, only one type is needed) can be sent on an exploration mission. They will be sent to explore a sea province, or a coastal province. When exploring a sea province, they will discover all adjacent sea-provinces on their way. When exploring a coastal province, they will discover all coastal provinces adjacent to the sea province in which the target coastal province's port is located. Explorers can only be sent on missions to provinces within your colonial range. Explorers may trigger certain random events while on missions.
My expeditionary fleet does indeed contain 3 light vessels and an explorer, so I get the "Send Fleet on Exploration mission" button. But when I click this, I just get a list of preset missions. Currently it shows only "Circumnavigate the Globe" which I don't have enough tech for, but a few years ago it also showed something like the Azores or Canaries which I was allowed to pick (but didn't due to wars with Portugal at the time). I don't really see an option to explore a province of my choosing like the wiki seems to imply.
Edit: Around 1531, I did get an exploration mission called "explore the coast of Greenland". Sending ships on this revealed the wasteland parts of Greenland (and triggered the Greenland natives event, but their name showed up as 's natives), but not the habitable province on the west coast. Because of this I suspect my game may be bugged.
Best Answer
This is actually a confusing issue because the DLC expansions wildly change the mechanics for Terra Incognita, and there is very little documentation about this on the wiki.
'Vanilla' EU4 Terra Incognita Discovery Mechanics
In 'vanilla' EU4, you discover new ocean provinces by moving a fleet with an Explorer on to the unknown ocean tiles. You also randomly reveal coastal land tiles when you move into an adjacent ocean province. To normally reveal land tiles, use an army with a Conquistador. An army with an a Conquistador can also directly disembark from a fleet containing transport ships to a coastal province with Terra Incognita.
DLC Expansion EU4 Terra Incognita Discovery Mechanics
If you have certain expansions enabled (El Dorado), the mechanics are almost completely different. Explorers can no longer move into Terra Incognita tiles at all. Instead, any group of 3 or more Light Ships or Transports will have a "Send Explorer" option which shows you a list of possible 'Exploration Missions'.
There are two different types of Exploration Missions. One is "Explore the waters of X", which sends the fleet out to systematically reveal ALL ocean provinces in the 'X' region. The second type of mission is only available after the first Exploration Mission is completed (or partially completed), and it is "Explore the coast of X", which sends the fleet out to systematically reveal ALL coastal provinces in the 'X' region. Which missions are available to you depends on your Colonial Range from one of your provinces to the region in question. You need a certain range to enable the first mission and a bit higher range to enable the second type of mission.
Comparisons and Conclusions
There are pros and cons to each approach. With vanilla mechanics, there is no limit to how far you could reveal Terra Incognita. You could take your very first fleet directly from Japan to Africa and disembark and conquer the Kongo. With the DLC expansion mechanics, this is impossible. However, you suffer no naval attrition damage when on an Exploration Mission. Some missions, like "Explore the waters of Australia" or "Explore the waters of Oceania" would take many, many trips for an Explorer to complete without the DLC expansion mechanics enabled. Additionally, unless you are using the disembark method, it can sometimes be hard to reveal the coastal land province you want using the vanilla mechanics, since the provinces you reveal are completely random (and not remotely comprehensive).
In my opinion, neither version is superior. I play with the DLC expansions enabled because the other mechanics they provide are excellent. However, if you were trying to do some very specific early exploring (for the purposes of pure conquest), I could see how the Exploration Mission mechanics would be limiting, since they are based on the premise that you would want to colonize the regions in question.
A Note About Full World Exploration
Note that there is no way (with either mechanic) to reliably discover uninhabitable land patches of Terra Incognita. You have a chance to discover them over time if you have a province near the area (or an ally does), but it's pure luck. It makes getting the World Exploration achievement annoying when you have 99.9% of the world explored and are only missing a patch of uninhabitable land in Siberia.