Page "Chindōgu" Paragraph 8

There are three key tenets to bear in mind in designing a chindōgu.

The principal among these are: ( a ) it has to be possible to make ( i. e., it has to actually exist ), in spite of its absurdity ; ( b ) it has to remain in the public domain ( i. e., it cannot be given a patent ); and ( c ) it must not be exclusively a vehicle for humor, or the warped satirical worldview of the inventor.

There is frequently humor in a chindōgu, of course, but this should properly be regarded as incidental, rather than as an end unto itself.