My first proper D&D campaign, a few years ago. 3.5 ruleset
I'm a fighter with a party of about seven other players. They're all practically veterans, save for my brother, a rogue. So were all just travelling along a road with our pack-mule in tow when we notice a narrow hole just off the side, with a weird blue glow coming from it. Being the curious types, we immediately tie off a rope and start descending down, one by one. Things don't go so well as half our party start failing their climbing checks and go tumbling down a lot further then they should. It is soon discovered that the cave itself was very steep, practically empty and the blue light was actually from a crap-load of boring fluorescent fungi.
Since everyone was having such a bad time moving around down there, I decided not to follow and just waited by the mule while the others sorted themselves out. This turned out to be both very lucky for the mule and bad for me, as a dozen or so kobolds suddenly swarmed over the hill, heading straight for me. As everybody was now stuck in that cave and tumbling down beyond the ropes length, I was pretty much reduced to fending them all off by myself while they tried to scramble back out.
Eventually, my brother managed to climb out of a different hole, halfway between me and some of the kobolds I'm shooting at with my bow. I end up accidentally hitting him three times.