Example of Emergent Gameplay

Skulking around the Black Forest when I run right into a Troll and the chase is on.

Here comes this fugly behemoth, crashing through the underbrush, leaving a trail of splintered trees in it's wake.

Backpedaling as fast as I can, praying not to get jammed up against some rock or small cliff, I'm lobbing arrows into the Troll like pew! pew! pew!

Apparently the ruckus gets the attention of a squad of Greydwarves who come sprinting in. Not to be left out, a small group of skeletons joins from the right.

Unbelievably, in all of the commotion, I've lost site of the Troll. Fine since I have a literal mob of mobs running me down while I sprint backwards.

I'm going to fucking die. I know it. Now I'm pew! pew! pew! into the crowd but it's not doing enough damage and a Greydwarf Brute is about to paste me against a copper deposit when …

BOOM! The Troll suddenly re-appears out of nowhere and, with one massive swing of the tree its now using as a club, it takes out every single one of my pursuers.

Then I kill it. Pew. Pew. Pew.

I love this fucking game.

What are some of your examples??