Dancey's devilment is a trick named after Charlie Dancey. He came up with that name because he wanted to have an alliterative trick (like Mills mess, Burke's barrage, Rubenstein's revenge, etc.) named after himself. When he wrote the Encyclopædia of Ball Juggling he included an entry for Dancey's devilment, but he never actually invented a trick to go with it.
In his book, Charlie Dancey claims that the trick came to him in a dream, but when he woke up he couldn't remember exactly what it was. He describes the trick as "a four or five ball pattern with the looping features of Rubenstein's revenge combined with multiplex throws of varying kinds". The illustration shows a juggler throwing a split multiplex under the arm with one hand, while the other hand does an orbiting motion.
Several versions of the trick have been invented by different people based on the description in the Encyclopædia.