In my teenage years, my DM was the sort who was much more interested in stories and imagination than she was in rule lawyering or power balancing. Consequently, our characters were often loaded the fuck down with inappropriately epic magical treasure.
One day she decided to have our party--fairly high level, I think our evoker was 14--encounter an army of goblins. Upon encountering the army, we discussed what it mean for our five person party. We decided that what it meant to be our level was basically such that any one of us could go for days on end slaughtering goblins (less than one hit die). But for an army we needed to use swarm rules, so that every so many, say several dozen, goblins together would equal a reasonable opponent for each of us given that they were an army and interested in working together to defeat their enemies. Our party was standing on a hill, and after a bit of conversation about swarm rules, our evoker (wizard who specialized in destructive magic) asked a question: "Which way is the wind blowing?" The DM considered this for a bit and said, well you didn't notice them until you crested the hill and saw them, so let's say a very mild breeze is blowing towards the army." Our evoker grinned at this and said, "okay, I cast Death Cloud." The spell creates a 100ft x 100ft cloud of death that lingers for the casters level in rounds and does a crapload of damage each round but also automatically kills creatures with one hit die or less. Our evoker said she wanted to shape the cloud to a 10000 x 1 ft rectangle starting at the front of the army. Our DM was thrilled and ruled that the breeze was sufficient to carry the cloud over the entire army in 14 rounds. All but a few dozen of the goblins were killed (the ones in the back who saw the cloud coming, had room to outrun it, and weren't too stupid to do so), those promply ran screaming away from the carnage of their thousands of killed companions. The DM awarded our evoker a level, and a forcible change in alignment from Good to Neutral. For being a fucking mass murderer: "those goblins didn't even see you yet, and now they're all dead. ". I said "corpse looting time!"