Nothing in Dwarf Fortress is ever simple. Even something as basic as building different types of rooms involves a few unintuitive steps. Where you might expect that all you need for a temple is an altar and the will to worship, in truth it actually involves properly assigning the space. Without this step, it won’t be fully functional, and your dwarves may experience a bit of spiritual distress as a result.
How to build a temple
Assigning a room as a temple isn’t particularly tricky, but it does involve navigating Dwarf Fortress’s nested menus in a slightly complicated way. The first step is assigning the room a meeting hall zone. You can do this in the zones menu (z.) Just select a meeting room from this list and then fill in the room you want to make a temple.
From here, you can add a new zone to the meeting hall by selecting it while in the zones menu and then selecting the icon (circled above) that allows you to add new, overlapping zones to existing zones. At this point, simply select a temple from the list of options and you’re well on your way to some soul-soothing prayer. Note that you can also assign a specific deity to a temple by clicking the icon next to the one marked above. early on, though, it’s probably a good idea to keep it non-denominational, at least until you have the space and resources for more specialized temples.
Temples are a great place to put an altar for your dwarves to leave offerings. They won’t reach their full potential, however, without containing some instruments. To add instruments, you’ll need to add storage space for those instruments, and you can even assign a performer to the room as well. Before your dwarves will dance, though, you need to make sure the total empty floor space in the temple is at least 25 total tiles.