I'm using build #423, I realize this is unreleased version but I figured I'd point it out.

The frequency of tar pits config is currently in general.cfg
I:"The spawnrate percentage of tar lake in the overworld"=25
I think it would make more sense to have it in worldgen.cfg

Also, the default value (25) is way too high. They are more frequent then water pools (see screenshot)

Yeah it's a bit unbalanced imo, I told @HurtsAsHell some time ago. We'll talk again about it

About the config entry: I'll move it eventually

Thanks for the report!

I'm playing metallurgy with the dame percentance and i haven't much bitumen lake. Could you tell me what percentance Is the best one?

Remember that the fluid tar governo only the Tar and bitumen ( one for the Road and One like the coal )

I refactored the cofig entry and
I tried lowering spawn chance to 20 ~
this issue will close as soon as I push the commit although this issue is open to further feedback

Water lake defaults to 4%.
As of 0.2.1 Tar lake defaults to 20%, which is way too frequent.
I feel tar should be less frequent than water lake, maybe like 0.5% or something.

mmh, 0.5 might really be too low, I'll make it 1% at first, and then I'll release a testing build so that people can tell me what they think about it

EDIT:
Since the old system was very limiting I opted for a rework, now spawnrate is in n/500 instead of n/100
Commit Reference: 41038d0
This change decreases drastically the spawnrate, I'm going to publish a testing build on my discord server with this new generation to check if people are fine with the new change

I just installed M4 and the config generated with tar at 250, which was way too high. It was a navigation hazard, it filled the basement of an Astral Temple. FYI.

@HurtsAsHell I turned it down to 25 and I'll test it out tomorrow. I just wanted you to know how dense it was for me in case this was unintended.
Sometimes I like to commandeer pregen structures for my first base and every single one was sitting in a tar lake. I'll investigate more and taken a couple of pics; maybe it's a mod interaction. Or maybe I'll just add some dinosaur mods. ;)

For me 250 for the tar it's ok but if you want you can change the config value @scribbler957 .

10 is good for us

I created a fresh pack with only M4 and Journey map and took a screenshot. Github's not letting me post pics right now for some reason, but it looked like the one above.

PS I'm guessing you're reusing the lake code from vanilla, but I think rarer, larger lakes would be cool.