A lot of people probably remember Lion Rampart as the company that first brought out the classic rpg Ars Magica, I'll always think of it as the outfit that published Whimsy Cards.
These cards were written by industry nobodies Jonathan Tweet and Mark Rein(dot)Hagen. I wonder what happened to those guys? Anyway, the basic deal was that you handed them out to the players and they used 'em to monkey with the plot of the game. Here are a few examples you can click to enlarge:
I remember using Whimsy Cards exactly once. Back in '92 or so I was a participant in a large multi-GM Champions game and I somehow convinced everyone to try using them for a session. As I recall it was a complete disaster. All the other GMs in the group took their plotlines way more seriously than I do. Being a site-oriented kind of DM, 'plot' in my games often boils down to the flimsy premise for this evening's dungeon crawl. A sudden alteration in the storyline is no big whup because I barely have a storyline to begin with.