gimmick - noun

a drawback or difficulty that is not readily evident

something unspecified whose name is either forgotten or not known

any clever maneuver

gimmick - thesaurus

catch   device   doodad   doohickey   doojigger   gismo   gizmo   gubbins   thingamabob   thingamajig   thingmabob   thingmajig   thingumabob   thingumajig   thingummy   twist   whatchamacallit   whatchamacallum   whatsis   widget