How we made the LEGO® SMART Play™ system

You may have heard some wild rumors about this new LEGO® SMART Play™ system. That it’s a ‘gamechanger’ for the LEGO System in Play. Or that it’s our ‘biggest innovation’ since the first LEGO minifigure in 1978.

We’re here to tell you… it’s all true.

From 2026, the LEGO SMART Play system will revolutionize the way we play with LEGO sets. It’s bringing creations to life by reacting precisely to how kids play – all without any need for screens. In short, they are LEGO bricks that play back.

Let’s dive into the incredible journey we went on to develop our highest-tech, most magical LEGO brick ever!

Where to start?

About a decade ago, we put our heads together to come up with a whole new dimension of LEGO play. No pressure, then. Back in 2017, we carried out a lot of research which revealed to us how kids were searching for a new way to physically play with their toys, in three key ways.

Firstly, kids wanted a toy that could allow them to play with their friends.

Secondly, it was important that their actions mattered and that the play responded to them.

And thirdly, kids wanted an experience that evolved over time to how they played.

To meet these needs, we needed a team that was ready to take what already made LEGO play great and then pioneer new innovations to take it into a new dimension.

We assembled an expert team from the worlds of video gaming, electronic engineering, industrial design, user experience, architecture, computing, sound… and much more. So, as you can imagine, a fair few ideas were floated. But one kept resurfacing:

Bringing LEGO play to life.

We wanted LEGO brick-built creations to come alive, reacting precisely to the way they were being interacted with. To have enough intelligence to recognize different characters around them and to truly play back. This was unknown territory for toys.

To screen or not to screen?

During early development, we briefly experimented with using cameras to trigger those kinds of reactions. But that would have required smart devices, which might take attention away from the physical play experience.

Instead, we challenged ourselves to create an alternative to screens. Something that could be physically interacted with in ways never thought possible before.

Prototypes, prototypes, prototypes

We made hundreds of play prototypes.

For this project to be a success, we needed to be sure it could add new types of play very broadly, while staying true to the LEGO System in Play. Hey, we make bricks! So that’s what we decided to do.

But to work out which functions the new bricks should have, we tried adding interactivity to... erm... pretty much every product you could name in the LEGO portfolio. Extending existing play patterns. Experimenting with new ones. This phase of exploration and discovery took months of back-and-forth between the play design team and our engineers.

Balancing the tech

One thing we realized from all this prototyping was that we had to make the tech feel invisible to allow the focus to remain on true LEGO play. So, we had a problem.

We had to make something that contained enough technology to come alive and play back... but without feeling so -tech heavy’ that it might dominate the experience and limit kids’ creativity. Today, you can see the benefits of us hiding the tech, every time a kid plays with a LEGO SMART Brick.

It feels genuinely magical to pick up a (seemingly) normal brick or LEGO minifigure and have it react spontaneously, dynamically and accurately to the way you play. All without seeing any pixels, cameras or much visible tech at all. But at the time? The question was more like, “How on earth are we going to fit all this into a 2x4 brick?!?!”

Making the tech invisible

So how did we squeeze THAT much tech into a brick small enough to stay compatible with as many LEGO sets as possible? We found a few SMART solutions...

For example, to charge the bricks, we needed to avoid wires, partially to keep the size down. So instead of plugging in, the SMART Bricks charge through a coil – like the one in your electric toothbrush.

We then realized that coil could also be used to detect SMART Tags. And if we used multiple coils, the SMART Brick would know which tag was closest to which coil. This might sound simple enough, but what our Innovation team had managed to do here was pretty seismic. They’d managed to invent an entire positioning system... from the ground up.

Each SMART Brick now knew precisely where every other nearby SMART Brick, SMART Tag and SMART Minifigure was in relation to itself. This meant they could react to each other’s presence, and know what position it was facing, whether it was being twisted, swung, thrown… anything!

Saved by the bell

Inventing a positioning system was a truly miraculous discovery (and we have the patent portfolio to prove it)… but it almost never saw the light of day.

After working on it for a couple of years without success, we set ourselves a deadline. If we couldn’t get it to work by that date, we’d go back to square one. The deadline came. And went. That morning, we agreed, reluctantly, to scrap it. But... the team just couldn’t help trying out one... final... tweak. And wouldn’t you believe it, the positioning system burst into life that afternoon!

Chip in

The benefit of knowing that we were trying to do something that has never been done before… is that we knew it had never been done before. So, when making the chip – the brain of the SMART Brick – we had to make the boldest decision possible.

Often with new tech, you rely on existing chips. We knew that an existing chip would save us a lot of time and money. We also knew it wouldn’t be the right call. Instead, we set about creating a bespoke, silicon ASIC chip. These were smaller than just one standard LEGO stud and highly specialized to the tasks required for the LEGO SMART Play experience.

It was an exciting day in the office when the first custom-made ASIC chip arrived. It was around 1 p.m. and we couldn’t wait until the next day to get started. “Just a couple of hours...,” we told ourselves.

Cut to 2:30 a.m. the next morning with a fully assembled brick with working audio! The first SMART Brick was born. Much pizza was had by all. (And a well-deserved lie-in.)

The sounds of play

One of the most exciting features of the SMART Brick are the sounds it makes. Different SMART Minifigures have different moods and reactions that are heard through the SMART Brick. The SMART Tags tell the SMART Brick how to mimic the sounds of different vehicles, spaceships, animals, characters and effects.

The SMART Brick also reacts uniquely depending on how it’s moved, twisted and turned. So we’re talking about a potentially limitless number of sounds it can make. Individual sounds usually require individual soundtracks. But we went in a different direction.

By breaking down just a few sounds to their most basic principles, you can actually carefully adjust their frequencies and amplitude to create drastically different end results.

So, you might hear our SMART Brick roaring like a jet plane or flushing like a toilet... but never realise they use the same core sounds. It’s what we call a synthetic soundscape – and it means there’s no limit to the types of sounds a SMART Brick can make. Which is helpful for us when it comes to making any future LEGO SMART Play sets...

Why LEGO® Star Wars™?

We had a lot of internal debate about how we were going to launch the LEGO SMART Play experience.

One reason was that kids often don’t need an introduction to Star Wars™. It’s second nature to so many. Meaning that as they dive into the limitless possibilities of the LEGO SMART Play platform, they don’t have to give a second thought to the galaxy they are playing in. We found that giving kids this starting point was a more effective way for them to get used to the SMART Play platform than a blank canvas. The characters they cared about helped fire up their imaginations. They knew how to use the starships in battle and got super excited when they heard the TIE Fighter make ‘that’ noise.

Battle play

While we’re on the subject, we were particularly excited to share the ‘battle play’ function with kids in testing. The early versions of this feature were quite well scripted, with kids able to do lots of different things in battle to help them win.

And kids loved it… for a bit. But when we made the battle play simpler and less scripted, kids were more interested, for a lot longer.

We realized that even though kids enjoy a starting point like Star Wars, the less we defined after that, the more they were able to explore and create for themselves using the SMART Play technology.

That’s the purpose of the LEGO SMART Play experience; to give kids the tools and the space they need to craft stories they never thought possible with physical bricks alone.

This sounds like a lot of new tech…

It is. No fewer than 25 (twenty-five!) patents have been filed. At its peak, the production line for the audio brick alone was as long as seven school buses, with around 160 workstations.

It’s a level of technical production we’ve literally never seen before at the LEGO Group.

Why have we pulled out all the stops? Because we truly believe we have made a step towards defining the future of play for kids. We’re not thinking about the next one or two years, or the next few sets. We’re thinking about the next century of play.

And it’s a journey that’s only just begun.