Sometimes it is indeed interesting to ask questions like when was playing invented?
Who was the first individual to play a game? And things like that, but for what we know these days, the answer may surprise some people: Indeed, there are only scant probabilities that playing is a human invention, but part of nature.
Many mammals play: Dogs and cats do that all the time, in front of us. Indeed, they are not playing poker, but they are playing anyway. Moreover: things seem to go a little further back in time as we explore the origins of playful behaviour.
A few years ago, a huge fossil bed was discovered in Montana, United States; there, thousands of fossilised skeletons of dinosaurs were found, mainly corresponding to the 'Maiasaura' species, which was an herbivorous, 10 metres long animal belonging to the group of hadrosaurids; they lived about 70 million years ago.
Soon it was evident that what was found was a colony filled with nests and individuals of all sizes and ages, including very young ones and unhatched eggs laid in clay or mud nests, which were also fossilised. This was a clear indication of social behaviour, similar to what can be observed today among birds or mammals: adults cared for their offspring, unlike what modern reptiles do.
Social behaviour implies a lot of things, and probably, also playing: the little newborns begin to play in order to develop some of their abilities. It seems that the maiasaurii did play, so this may well be the first and oldest indication that playing is not only part of our life, but of nature itself.Related: Origin and Development of Games. Gambling and betting systems