Play was defined as an unstructured activity outside of school, such as backyard cricket.
More than one in three children said they had no one to play with, one third said they ran out of ideas for play, and parents said children struggled to amuse themselves without electronic devices.
Professor Grant Schofield, director of AUT University's Centre for Physical Activity and Nutrition, wrote in a foreword to the report that the findings were "astonishing".
"Children need to 'unplug' and venture into the backyard to let their imagination run wild.
"Let them take some risks. Let them make mistakes. This is how they will learn."
PLAY TIME
46 per cent of children aged 8 to 12 not playing every day.
Sedentary and structured activities such as sports training blamed.
Unstructured play key to healthy brain development.