Was somewhat inspired by "Animal Justice" that triggered a link to "Avatar the movie".
The idea is to shift the lime light away from the underground mining which is predominantly dwarven, to say allow either something like a colony of elves or just dwarves turned into tree-hugging hippies.
The idea, is to make giant trees, which are not like the normal trees which are just 1 tile entity, but have physical 3D structure in the terrain. E.g. imagine a whole magma pipe turned into "wood" type of material (when "mined" ) and pull that whole thing half way above ground, (above ground is the tree trunk, those that remains underground are roots). Then high up, we can have some vertical "branching, using the "wood" type material again, and end with leaves (which may not be visible, but would be interesting if it can become some some sort of semi-persistent farmables). Those part that remains underground will also have "branches" which are roots. (i.e. the trees will have to be generated during the time stuff like magma pipes are generated)
As a kind of organic dynamics, giant trees lives forever even without water (they just become dormant without any leaves) When there are place to grow leaves and some root part is in contact with water, it will slowly ABSORB the water at the root, and "grow" leaves automatically. Would be interesting if banches, trunk and root can grow too, but it can be taken that the growth of the giant trees are so slow that it is not detectable in the lifespan of a dwarf. (until the time where terrain changing dynamics like erupting volcano is done, then perhaps actual tree growing can use same dynamics).
What does it enable in-game?
- Tree-colony style playing
- When tree trunk/branch/root tiles designated to "mine", it will require "woodcutter" skill instead of "miner" and yields "log" (perhaps a raw kind of wooden block?) Perhaps smoothing/carving should require carpentry skill while engraving should require the "wood crafter" skill?
- carve/"dig" rooms in large tree trunks (maybe not as large as underground, but you get many levels!), open platforms that extends of edge of tree trunk/branches, linking walkways that links between trees above ground (it is also possible the giant trees which are closeby and have large crowns will have branches that naturally "touch" each other forming natural linking walkways)
- tree-huggers who are opposed to actually harming the wood can grow their colony by building AROUND the trunk (e.g. a spiral stairway consisting of up/down stairs and open walkway that spirals up the surface of the trunk, and have larger platforms with housing on the branch levels (which have more horizontal "terrain")
- leaves can be seen as a kind of harvestable wild "plant" by itself, except that it cannot be planted and will always grow some the same region, tied to the tree's nutrition (water intake at the root)
- Tree roots can be used as a natural water-sink that spans z-levels
- shift of defense focus : from mainly against "OUTSIDE" and "ABOVE" to "SURFACE" and "BELOW"
- Although a well hydrated giant tree is somewhat harder to burn, a dehydrated tree or persistent fire sources may become a bad, bad combination. But since there are around for so long (at least as long as any race or megabeasts or even older), there must be some sort of natural counters. Could add more to the fire dynamics (I'm out of idea here atm) If not, the possibility setting the whole tree colony on fire could either provide some glee for some evil dwarf, or woe for some hippie elf (Avatar the movie?).
- Elves could REALLY be the "natural" "white-cells" of the giant trees, evolved to get rid of the bad thingies that will try to harm the trees.
- rope ladders? retractable staircase that spans z levels in open space, but can be "drawn up" as if a drawbridge. helps to keep non-flying enemies on the ground away from tree colony during invasion.
- elevator ? like a bucket in a well, except that it can transport people. fancy version of rope ladders that can span many more z levels.
Other story-drivens beyond usual dynamics:
- special anti-tree invasions: e.g. enemies which includes some special task force to set fire at certain important sport: the defenders better get rid of them in time (hmmm.. it seems that I MAY be uncounsciously affected by Avatar the movie)
- special underground raids that intends to harm important parts of the tree roots (more susceptible to dwarf fortress which digs to expose roots and joins up with surface or some underground carvern with possibility of invading nasties). Or even let the players themselves harm the giant trees. (though what is the exact effect of harming roots beyond lessening/limiting leaf growth is not decided atm... maybe won't have effect on anything except leaf growth... even when dying, the giant tree will take so long to die that it could still outlive a dwarvern generation or tree)
- Giant Tree Spiders!!!!!!
- more possibilities when magic arc comes in. Giant Trees like this heavily modifies the "mana" concentration or flow or whatever magical crap.
- monkey colonies? or giant tree-specific eco-culture (like similar before for carverns)
well, that's most of what I can rem off the top of my head atm. feel free to discuss, criticize, add on. If we get Toady interested enough, it may come up in some future DF versions.
more idea images: