I encountered my first cavern troll yesterday. Luckily, the one to bump into it was my militia captain with a copper shield, copper helm, one or two peices of bone armour and a steel battleaxe.
The first "Oh shit, a Troll!" move was to chop off it's left horn. I activated the rest of the squad (just one other macedwarf with a copper buckler, pitiful armour, and a -silver mace-) and ordered them to kill the troll. The macedwarf spent the entire battle being useless, "gathering equipment". The toussle with the troll ended with one yellow wound on my militia captain and a red wound on one of his toes. He isn't moving around, but he's not dead or bleeding out, I think. The only other damage he was able to inflict on the troll was to chop off it's left hand.
After my militian commander stopped moving (presumably because of his mangled toe), the troll went to go hide under the stairs. My expedition leader then comes down to pick of some silver ore, but he gets attacked by the troll. As this is happening, my woodcutter goes to the level to pick up some ore. After stupidly hoping that the militia commander would get up and finish killing the troll (it was pale from blood loss), or that the macedwarf would finally get his ass down to the caverns, I drafted the woodcutter who already had a battleaxe and sent him after the troll. He chopped the other horn off and turned the troll into a mangled corpse.
The expedition leader had a mangled upper spine and died of suffocation. First death of the fort. I'm still cleaning up after that debacle.
Also, this was the first thing that happened after I got soundsense up and running.