Running a campaign during my last deployment, my party decides to travel back through a jungle they had explored to see an NPC for information. The group is mostly melees, so it is both easy and hard on me. Easy because they don't have spells, hard because they don't have spells. You get the picture.
So I decide to have them ambushed by gnolls the same as they were last time. I want them to get a little revenge as they got sniped a bit but couldn't catch the enemy last time. So it's deja vu all over again as they are rowing to shore. Until the bard asks "Are we within 440ft of them?"
Sure, I say. Why the hell so specific? I've forgotten what a couple levels can do. You can probably guess what happens.
Bard Dimension Doors the cleric, fighter, and monk right behind the ambush party. Gnolls don't notice, slaughter ensues. Completely surprised me, the party had a morale boost, mission accomplished.