this would fit into a MMORPG as to provide a new way of the usual \"click click click\" sydrome of mining. just because its a repetative task doesn\'t mean it has to behave like a repetative task. with this its \"click click \'oh, no more ore\' *move to another part of mine* click click\" and it gives multiple jobs to multiple classes. it can even be a great place to put a quest in...
Think; A fighter, mage, miner, and builder all head into a dungeon mine to retrive a peice of a mineral (some soap stone, lets say) and they all go in. the fighter + mage kills off all the enemies at the front of the cave and such so that the miner can clear out the dirt in safety, and the builder prop up the just mined and stop any chance of a cave-in in the area. as the 4 make it through the place, they stumble upon a mineral node. the miner from experiance knows that it isn\'t the mineral they are seeking and they continue on. the miner hits a wall face and *crumble* there lays a open cave room. some giant spiders here-and-there which the fighter kills off with ease but its too dark so the mage casts a light spell to light the place up.
and there it is! in the middle of the cave, a boulder that gleams with the mineral they seek! they all head in, and get some of the ore, but when they are heading out a thunderous roar erupts from the center of the cave and the big boulder becomes alive! they all run away as the beast tears the builder\'s supports usunder, causing a cave in that not even the supports can stop (hey, a new cave creature spell!) and they all run for their daintly little lives and make it out alive. with mineral in hand the 4 head to the old man and and claim their prize. the end.

the \"dirt\" nodes do not respawn. the cave-in nodes do though, which is why you need a builder to put up supports.

there are no differentiations between dirt and cave-in nodes, so until the spikes apear you wont know.
(and the supports last longer than it takes for the ceiling to collapse, so as soon as the supports go and wait a hour later... *squish* for any NPC

(PC\'s still get pushed away, though. \"OMG I GOT FLATTENED! NERF IT!\" would not look good spammed 100 different ways 1000\'s of times a day on the forums would not be fun))