How deep is the Underdark?

[RUMBLETiGER]

I'm sure to some degree the answer is "It depends" or "However deep the DM wants", but I'm trying to get a reasonable range of how deep down the Underdark layer typically is. Can anyone point me to any official references to that layer that indicates Depth? Thanks.

 

[ImperatorK]

Which setting?

 

[Treebore]

1/4 mile to 1/2 mile. For heat loving creatures you can go down to the molten core if you want Elementals, etc... walking around.

 

[Sekhmet]

In my Faerun setting, the Underdark connects to the first layer of Hell by way of a tunnel system.
It was the only way, I thought at the time, to account for such an increase in the CR of creatures in the area.
Nothing was environmentally dangerous enough to warrant it, and there is so much Demon/Devil culture in Drow society that it really seemed necessary.

 

[ImperatorK]

In my Faerun setting, the Underdark connects to the first layer of Hell by way of a tunnel system.

Hell is on a different plane.

 

[RUMBLETiGER]

Which setting?

Since my homebrew setting steals from other settings like a raccoon, Any reference to depth in any setting is just fine.

1/4 mile to 1/2 mile. For heat loving creatures you can go down to the molten core if you want Elementals, etc... walking around.

This sounds good, can you point me to a source of this info?

In my Faerun setting, the Underdark connects to the first layer of Hell by way of a tunnel system.
It was the only way, I thought at the time, to account for such an increase in the CR of creatures in the area.
Nothing was environmentally dangerous enough to warrant it, and there is so much Demon/Devil culture in Drow society that it really seemed necessary.

Sweet idea.

Hell is on a different plane.

Note that he said, "In my Faerun setting", all DMs get to call such shots.

Any official sources would be appreciated. Thanks for the input.
I'm working on a campaign that involves Dwarves, Elves, Humans, Half-Elves, Shifters, a large sinkhole, a Mithral mine, Greed, Drow, Skirmishes, Underdark, Exploring, Formians and the plane of Mechanus.

Good times.

 

[ImperatorK]

Note that he said, "In my Faerun setting", all DMs get to call such shots.

I'm just saying in case he didn't know.

 

[Sekhmet]

Hell is on a different plane.

I'm aware of the difference between the Prime Material and Baator.

 

[Sekhmet]

According to the Forgotten Realms wiki, the Lower Dark is 10 miles deep and lower. The first three miles are the Upper Dark, where not much exists but kobolds and goblins and such. Three to ten miles down is the Middle Dark, where most cities and Underdark dwellers live.

 

[RUMBLETiGER]

According to the Forgotten Realms wiki, the Lower Dark is 10 miles deep and lower. The first three miles are the Upper Dark, where not much exists but kobolds and goblins and such. Three to ten miles down is the Middle Dark, where most cities and Underdark dwellers live.

Ah, thank you. Found It Here.

Following the footnote, it points to the original source as the 4th edition Forgotten Realms Campaign Guide.

Being a 3rd edition guy, I went to the Forgotten Realms Campaign Setting book, and read up on the Underdark starting on page 210. The 3.0 version broke the depths into 3 layers as well, but didn't assign how deep. One example of an ecosystem placed a giant fungus in a cavern 1-3 miles deep.

Works for me, thanks!