1)When the plot of a movie is completely and utterly ruined by a god awful director. Usually based on a good book which is totally murdered.
2)When a secret scheme to get something (usually illegal) is ruined by one or more idiots.
3)When a small area of land is ruined by a gardener who is trying to be self sufficient because its fashionable, but screws up instead. Or they are just a bad gardener.
1)'Dude I watched Angels & Demons over the weekend!'
'Oh man, thats 146 minutes of your life you'll never get back! It was such a plotfuck!'
2)'I was plotting to get revenge on my brother by putting his hand in warm water. He found out before I did it and I got grounded. It was such a plotfuck!'
3)'I read about self sufficiency in a hip magazine but I plotfucked and now I just use it as a dump. Its great!'