One's just opened at my local primary school complete with tunnels, a dry creek bed and undulations that children clamber around, and play games that they create rather than have created for them.

Being an unfenced public school, it shares the space with the neighbourhood after school hours and on the weekends, making the school more secure.

At nearby Ainslie Primary School there are now two so-called 'play pods' - shipping containers packed with things such as milk crates, crutches and loose wheels. The contents are neither entirely safe nor totally dangerous.

With children as young as six about to be subject to national tests on what they've learnt, play has never been more important. Unlike tests in which there are right answers, undirected play is open, not closed. It allows children to develop their own rules and to learn at their own rates. It actually helps them become smart.

Play, unmediated by rules or technology, has been shown to:

Play isn't just for kids but adults too. Google does it, installing pool tables, graffiti boards and slippery dips in its HQ. Part of my training as a mature-age student at the ANU School of Art involves letting go of outcomes, and playing with material from paint to found objects.

I once worked with a set of crutches just like those in the Ainslie play pods.

A growing chorus of educators, public health advocates, architects and landscape designers are raising concerns about children's lack of exercise and the safe, sterile and increasingly commercial environments they play in.

In New Zealand, at the instigation of public health professor Grant Schofield, disadvantaged schools across Auckland have turned disused fields into adventure playgrounds complete with junk such as old tyres and fire hoses as part of an experiment that bans rules about what can or cannot be climbed on. With the support of principals and teachers children are allowed to roam wilderness areas adjoining schoolyards and are encouraged to bring bikes, skateboards and scooters into school.

Schofield says children develop their brain's frontal lobe when taking risks, allowing them to calculate consequences.

Students are using old equipment imaginatively, unpredictably. Teachers are observing greater cooperation.Their concentration has improved. There is less conflict. The children identified as bullies are busier, less bored and better behaved. In trusting children with risk, the schools have allowed them to discover for themselves the boundaries of what is possible and impossible. They've grown in confidence and they are better able to learn.

In the world these children inherit, computers, robots and algorithms will do much of what was traditionally thought of as work; even journalism, legal work and counselling. What will matter most will be critical thinking. Creative play is one way to get it.

It's important to reclaim play, in order to ensure that children learn more than stuff; they learn how to put it to good use.

Toni Hassan is a student at the ANU. She is also an adjunct research fellow with the Australian Centre for Christianity and Culture, Charles Sturt University.