Firstly, I apologize if these observations and research have been covered elsewhere. I did a quick search and didn't see this in the modding board, and that sort of embarassing mistake happens here from time to time. If not, I may have stumbled upon one of the most significant undocumented changes to the way the raws work yet. Anyway...
Shortly after 31_01 was released, I was disheartened by the fact that METAL_PREF no longer appears to help determine metal usage. At first glance, between this and the lack of MINOR_METAL, it appeared a portion of my upcoming megamod would be unimplementable.
However, when I was looking through some other threads (might have been on the bug tracker), someone mentioned that humans can only make use of bronze and a few minor alloys. One observant commenter noticed that humans lacked a permitted reaction tag for steel and whatnot. Another commenter, however, that dwarves can use iron while humans cannot, and unlike steel, iron smelting was defined from the iron ore raws rather than the reaction files, and PERMITTED_REACTION tags do not exist for native ores. Also, my own tests revealed that humans also cannot make things from tin or copper, the two components of bronze. This oddity, along with the rest of the previous two paragraphs, led me to a series of additional tests that led me to a rather startling conclusion or two.
- Firstly, a race's access to alloys -- metals such as steel and rose gold, which are not found in ores -- are determined by a race's [PERMITTED_REACTION:x] tags in the entity file. I think this was implied already, by the information in the last paragraph.
- Secondly, a race's access to ore metals -- metals such as iron and copper, which can be found by smelting ores such as hematite and native copper -- are determined by whether or not the race has the [STONE_PREF] tag.
- The above two are independant of each other; if a race does not have access to the ore metals required for a reaction they can use (as is the case with humans and copper, tin, and bronze), they can still use the alloy. This may not be the case in all situations, but they can embark with bronze, their shops have bronze, and I think their soldiers have bronze too.
As I previously said, earlier this month I was worried that metal availability by race would be much more difficult. However, given the above conclusions. This is not the case; rather, the exact opposite is evident:
In the DF2010 generation, Dwarf Fortress modders have far more control which metals an individual race can use than we ever had before.Use the information in this thread as you will. Mind you, if anyone can refute my findings, please do so.
One mystery I've yet to solve: when I play a dwarven adventurer, I generally start with bronze. More research may be needed.