Mining is dangerous ...

[veinslayer]

why not miner related quests? such as....
random dwarf miner: wow this rock has writing on. Says something about hidden treasure or something....
Zooljin: where the hell am i?! (had to through that in there as i am usually lost in a mine looking for things to kill)
RDM:hey klyros, help me look for this hidden thingy
Zooljin: sure why not...if there's anything to fight i'll kill it. just dont expect me to give directions
RDM: say do yah know where....
Zooljin: god damnit cant anyone listen to me?! i have no sense of direction! 
 and random clues lead you along paths not accesible unless you have the previous clue, one leading to another until great treasure or random junk or a critter is found.

[Erisnas]

Good idea, but you should start out taking tutorial type quest like crafting from Harnquist.  If that works well then miners might soon be great questers as well!

[Ravenguard]

As far as digging something up that gives you a quest, what about 'binding' it to the person?  Or what about the act of digging it up brings the 'You got a quest!' thing, and so, the item you got helps you finish the quest, but you have to get the quest in the first place?

So...
Player: /dig <something>
You got a quest!
Player:  *looks confused, rummages in sack and pulls out item*  Ooo... cool.
Other player: Wowz, you got that magical quest rock!  I want to buy it off you!
Player:  K.  *sells magical quest rock*
Other player: But it's not giving me a quest???
Player: *shrugs*

[aersixb9]

I vote for deformable terrain. Then players could "dig" mines into the ground anywhere! (preferably close to cities...) Vast tunnel networks would form, and there would be rampant cave-ins and water management issues (since the water table is pretty close to the surface in most places where humans live)...

That being said, if deformable terrain is too difficult to program (I'm not volunteering for that project!) then how about a nice (or several) pre-rendered mines with different cave in points. Then the mine would start out totally caved in, and players would have to clear it to get to the depths. Instead of digging for specific things, you'd just "dig" anywhere in the mine, and then you might find something depending on how deep you were in the mine! So if you're near the surface, then you might get some clay, but if you're 1km deep in the tunnels you might find coal and iron. There might even be hot spots (like a coal room?) near the surface...although to balance it, there should be dangers on the way to the hot spots that are comparable to the reward of getting the item...

Digging out the cave-ins would be accomplished with a pick-axe, magic, or some combination of the two! Then the cave-in zone could be reinforced by crafters...or something like that.

I'd like to see a more elaborate mining system - one that is at least as complex and fun as the combat system.

[Ilirion]

Digging out cave-ins would be a tad bit difficult, wouldn't it? How about small cave ins that are reset (as if they were dug out by guards or miners) in about 2 days and bigger cave-ins that take about weeks to dig out?

[Erisnas]

That is a good idea actually, especially the second revised version.  However, I wonder how many people would get annoyed about who has to start the mine after a cave-in.  I have to wonder when cave-ins would happen.  In an elaborate mine like that you would constantly have people in there.  If a cave-in occurred perhaps you were given a warning (sound, rocks falling) then you had so long to get out.  While it might help prevent macro-diggers, some may find it very annoying since you could have set aside a few hours to mine gold but a cave-in occurred while you were digging.  The rest of the time would have to be spent just getting back into the mine!  I don't mine too often but I can see that issue arising.

[Lirreka]

That is a good idea actually, especially the second revised version.  However, I wonder how many people would get annoyed about who has to start the mine after a cave-in.  I have to wonder when cave-ins would happen.  In an elaborate mine like that you would constantly have people in there.  If a cave-in occurred perhaps you were given a warning (sound, rocks falling) then you had so long to get out.  While it might help prevent macro-diggers, some may find it very annoying since you could have set aside a few hours to mine gold but a cave-in occurred while you were digging.  The rest of the time would have to be spent just getting back into the mine!  I don't mine too often but I can see that issue arising.

Wouldn't you still find occasional gold ores as the mine is being cleaned up? After all, since more earth filled the cave tunnels, wouldn't there be new veins of gold ore where once there was only an empty tunnel.

[Erisnas]

Yes, but some want just the gold so they would only mine when the mine is at its deepest.  However, I do think this idea could be applied elsewhere.  One location could be at the BD.  Some caved in tunnels could be re-dug for short cuts!  Also the best place for a mine like this to be implemented first is also near the BD.  There is a caved in tunnel near their that I am sure would have some thick ore veins.    Also, since it takes a long and sometimes dangerous journey to get to it may offer different advantages to the entire game: the BD may become a trading post often used by players, create similar experience to the ones often talked of at Levrus's mine, and creative players may give birth to some more as well.
   However, this is something that wouldn't get implemented for a long time so I hope it doesn't get forgotten.

[Camazotz]

for the toxic gases, shouldn't they slowly kill you, so if you get out with enough health, and it wears off or you get the antidote or something.