So... I just hit magma... bah... I looked for it! I dug like 150 levels until I got some warm, and now I realize I have no idea what to do with it.
Any advice on how to handle the thing?
Thanks!
Magma is excellent for powering certain "Magma" named workshops as well as working into your fortress defenses.
What I do to tap into it is to create a pipe at the same z level as the top of the magma. To break the final wall to fill your pipe you can either gamble the life of one of your miners and just dig through it, or you can channel it out from above. Once magma is flowing into your pipe you can pump it wherever you like.
Anything that touches magma, however, has to be magma proof. There is a list of magma-proof materials on the wiki if you don't want to guess. One fort I was in, I created a pump stack 130 levels high to get magma from the depths all the way to the top of my fort. During sieges I would dump it on the attacking forces. It was good fun. :)
To break the final wall to fill your pipe you can either gamble the life of one of your miners and just dig through it, or you can channel it out from above.
A trick I do is to dig a tube to magma on the same Z level, and smooth the wall instead of digging through it. Then, carve a fortification in the wall. You can still loose dwarves this way but for some reason I feel like it’s safer. Might be my imagination but I rarely loose dwarves doing this.
It will not keep magma creatures from traveling through the magma at the fortification, if I recall correctly. Creatures can move through submerged fortification.