Simplify the following text for a Grade 10 native English-speaking person.
Original: The Shanghai Fugu Agreement ( German : Shanghaier Kugelfisch-Abkommen ) was a successful 1985 political prank played on the Social Democrats in the German state of Hesse .
Simplified: The Shanghai Fugu Agreement was a successful political prank which was landed on the Social Democrats in the German state of Hesse in 1985 .