I've often wondered how it is that LEGO goes about creating new sets. I can easily imagine a person sitting in a room all day with unlimited pieces of every shape but with some of the complicated sets we see these days there must be some sort of computer aid.

Do the designers model new sets on a computer which then figures out pieces and instructions or do they do build and tweak until things seem just right?

Can anyone provide insight into the process that LEGO takes on creating new sets?


7 Answers 7


I once had an acquaintance who worked at Lego as a product designer (I don't remember his exact title). His job was, simply put, to come up with new sets. There are some general constraints – balancing the different Lego worlds/themes (contemporary, pirate-age, Star Wars, Harry Potter, etc.), hitting certain price points/box sizes (limiting the number of bricks in a set), coming up with sets that work well together, targeting different age groups/motor skills etc.

LEGO also tries to design the individual pieces to be used in many settings. The same terrain/foundation was used with different paint for the anti-pirate fortress (which my sister had) and the dragon knights castle (which I had). In the old days it was fairly rare for Lego to make new brick types – it has become less so, as their manufacturing processes have become more nimble and less expensive.

As for the software used in designing LEGO sets, I know little about it. They do use software/brick simulation, but also work with the physical bricks, especially the old hands :)

  • Why is it less expensive? Lego almost went bankrupt from inventing too many new parts in 2005.
    – Erik Olson
    Commented Oct 27, 2011 at 0:07
  • 5
    I have a hard time believing any manufacturing process, even if kept primarily in European countries as LEGO has done, has not become cheaper and more flexible between 1940 and 2011.
    – user23
    Commented Oct 27, 2011 at 0:27
  • There's a lot of efficiencies from new technologies – more precise, computer powered tools, less labour costs from using robotics for certain tasks – and I don’t think it was the creating of new parts themselves that brought them close to ruin, more the fact that they couldn’t sell them and burned a mountain of cash marketing failed products. Remember Galidor, Clikits?
    – mikl
    Commented Nov 1, 2011 at 19:18
  • 1
    3D printing for prototypes probably helps reduce costs too, as real molds only need to be created for final version of parts.
    – Joubarc
    Commented Feb 9, 2012 at 15:02

As far as I know, designers work mostly with bricks only.

They do have a desk and a quasi-unlimited supply of parts (which I think is actually not too exactly close to their desks), and usually use their imagination the same way a fan does.

Something which fans don't do however, and which designers must do, is keep track of the price of the model they're building so that it's in line with the expected price point (these are determined by marketing when a theme is started).

This is much more complicated than it sounds, because element prices aren't always logical (for example, a Technic axle 5 is cheaper than a 4), and the number of different elements counts too (that's why sometimes they use other parts than what would be logical, such as a 1×2 brick with groove when the groove has no purpose whatsoever at that place, but since the brick is already included elsewhere and a regular 1×2 isn't, it's cheaper to use).

In short, all production costs are taken into account, including packaging and so on. Of course, for parts which aren't produced yet, the prices is much higher, but how higher depend on a lot of factors (whether the part exists but not in that color, whether the parts fit well in the system, and so on). Design teams may also want to bargain with other teams to have them support the cost development of a new part. Licensed themes may have a different cost structure because the licensees are sometimes willing to pay for a new part if it makes the model more realistic (most good hairdos come from licenses nowadays).

Once the designer has a model ready (it'll undergo quite a few tweaks along the way, of course), they'll hand it to another team which will be responsible for making sure the model can be built by kids, and possibly tweak it some more to make the instructions clearer (ever noticed why some hidden bricks have sometimes unexpected colors?). These guys do use computers, and they'll make the instructions as well; but in the meantime the designers are busy on their next model.

  • What is your source for the answer? First hand experience?
    – Mike
    Commented Nov 2, 2011 at 15:22
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    Not first hand per se as I'm not a designer myself, but this information is gathered from conversations with some designers, and with people who attended fan workshops in Billund. The only thing I can't really remember having been told explicitely is the bargaining between teams; but it's true that the cost of a new element has to be supported once only. Again, elements which fit better within the system will be more readily accepted for production anyway.
    – Joubarc
    Commented Nov 2, 2011 at 15:40
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    You may also want to read designer Mark Stafford's interview which provides a lot of insight on this as well - including the reason why the Technic axle 4 is more expensive.
    – Joubarc
    Commented Jan 9, 2014 at 8:15
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    When Jamie Berard came to Brick Fiesta in Houston in 2012, he mentioned the bargaining between teams. This was demonstrated in part by one of the prototypes had the conical hat for the wheel covers for the latest incarnation of the Sopwith Camel (10226).
    – gev
    Commented Jan 10, 2014 at 20:49
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    This seems about right from a talk I attended recently about the design of a Nexo Knights set (brickset.com/article/18161/70315-clay-s-rumble-blade-prototypes). Process was roughly: take ideas for a set, go into the vaults, pick parts currently in production, build, iterate. Multiple designers may work on a set, more than one prototype can be considered concurrently - final design incorporates ideas from each. Play features, ease of building, cost factor in. New parts are 3D printed (often overnight). TV shows / computer games get late but not final renderings of the IP to incorporate.
    – mrbaboo
    Commented Dec 15, 2015 at 10:18

I thoroughly enjoyed National Geographic's documentary - Megafactories - LEGO:

It's one of the most popular construction toys in the world. In the age of unprecedented competition for their attention - from videogames to TVs to countless activities - children still spend over 5 billion hours a year playing with LEGO bricks. But building simple modular toys with interlocking bricks is a lot more complex than it seems. Their most popular set - the police station - is completely redesigned every few years to keep up with the times. From R&D and engineering to robotic assembly lines and the most fickle test market on the planet, Mega Factories: LEGO takes you behind the scenes as a real life police station turns into a playground for the imagination.

  • 1
    Mega factories - gotta love the irony...
    – Joubarc
    Commented Feb 9, 2012 at 15:04
  • 3
    "This video has been removed by the user. Sorry about that."
    – mbx
    Commented Apr 8, 2012 at 11:51

There are a series of youtube videos about LEGO Cars set design process. They are kinda simplified and targeted at kids, but still have some good insights in process. First video can be found here.

Playlist of all 6 videos somebody have assembled.


It is actually super complex. They first start by tinkering, when they have an idea. Then they start building. When they have the object built, they rebuild it step by step, gluing each step to a board. Then a device scans the boards for changes, makes the instructions, and calculates part count. Or at least that is how they used do it.

How do I know this? I read it in a book by 2 former Lego designers. Called Forbidden Lego, you can look it up on Amazon and preview the pages where it has the info.

  • I have some doubts about the gluing and scanning part, to be honest - as I understand, designers will indeed first make their model with actual bricks, going through several iterations depending on unknown factors (cost, target audience, marketing, whatever); but I believe they'll make a digital version of it (with what I suppose is some in-house software similar to an LDraw editor) when they hand it over for the next steps. That said, since Ulrik Pilegaard stopped working for LEGO in 2004, it's possible the method has changed and they did in fact work the way you say back then.
    – Joubarc
    Commented Jan 31, 2014 at 10:54
  • @joubarc Thank you for your comment, I do realize that they most likely do it a different way. Thats why I had included 'at least that is how they used to do it'. However, that being said, I will edit the post and include another line explaining how this way is most likely not in use anymore.
    – JVarhol
    Commented Jan 31, 2014 at 11:00

This is what the official website describes:

Our designers in Denmark create and test new LEGO® sets, toys and themes every day. We work hard to make sure our toys are surprising, fun and can be passed down for generations!

First, we come up with the idea for an exciting new theme, like LEGO® Elves, or a new series within an existing theme, like LEGO® City Volcano Explorers. Then the design team works on coming up with different sized sets with loads of cool features that will appeal to a wide range of LEGO® fans.

Once they’ve figured out what kind of sets are the right ones, they’ll build those ideas using existing pieces, and sometimes design new LEGO® pieces when necessary. We do lots of testing to make sure the sets are fun to build and play with and can stay together when they’re flying or driving around.

Then, it’s on to designing the instructions, working out what sort of boxes the sets will need to go in, and determining what pictures will be on the packaging. Finally, we ship the finished sets off to all the stores!



Do the designers model new sets on a computer which then figures out pieces and instructions or do they do build and tweak until things seem just right?

As I understand it, their modern process is a mix of both real-life and digital building. Building a physical model is important for testing durability and such, while digital building is helpful for quickly testing different color schemes.

For digital building, LEGO uses their own in-house Easy Builder Tool which is an Autodesk Maya plugin. From what I understand, LEGO Digital Designer is somewhat based on this tool, except it doesn't use Maya and the parts have reduced resolution.

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