These sorts of Uno Reverse Card moments are both frustrating and gratifying to me as a DM. I of course try to roll with them, but occasionally they do mean I need to toss out half my mental notes for the rest of the campaign and seat-of-my-pants a whole new plot branch right in the moment.

There was one campaign I was in, I’d estimate it lasted about five years of real time, where my character stabbed the final Big Bad of the campaign with a weapon that we had picked up in the very first adventure of the campaign. We’d been toting it around ever since then without using it because it seemed like a very special purpose item. It wasn’t pivotal to defeating her but it was still fun to tie the campaign together like that.