Lots of people have played with LEGO at some point in their lives. This is good for designers since it means lots of our stakeholders have a hands-on understanding of how a collection of simple pieces with a common structural framework can lead to the assembly of more complex (and useful) artifacts. In other words, LEGO is a fun modular framework that many people are familiar with, which is why (at least for me) it comes up often in conversations with clients.

While I’m not an AFOL, I have three kids who love the system — as did I, when I was a kid. My children and I spend much of our play time together building treehouses, spaceships, pet shops, and other fantastic things with the little bricks.

LEGO pieces come in many colors, shapes, and sizes. That said, I’d venture if you ask anyone to “draw a LEGO,” they’d produce something that looks like this:

Image: LEGO

Image: LEGO

I consider this the prototypical LEGO brick. The 2x4 stud grid is big enough to illustrate the framework (in a way the one-stud brick doesn’t, for example), but small enough to be useful in a variety of situations. (That is to say, longer and/or taller pieces are less flexible.) I think of this brick as the most “LEGO-y” of LEGO pieces; it’s the one that best articulates the essence of what LEGO is.

Over the last couple of decades, the LEGO company has produced sets that include a variety of one-off pieces such as this one:

I think of pieces such as these the opposite of the 2x4 brick. While this raft has the studs that make it compatible with other LEGO pieces, it’s not LEGO-y at all. Where the brick is useful in a variety of situations, the raft is very constrained: It dictates how you should play with it in a way that the brick doesn’t.

The LEGO framework is based on rectangular prisms with standard dimensions:

Image by Cmglee via [Wikimedia](https://en.wikipedia.org/wiki/File:Lego_dimensions.svg)

Image by Cmglee via Wikimedia

The more a LEGO piece diverges from this basic form, the less useful it is. That doesn’t necessarily mean it’s not fun — it means it’s not a very good citizen of the system. What you want in a LEGO piece is possibilities: applicability to a wide range of situations. The simple rectangular volume can be part of a castle, a nuclear power station, an ice cream shop, a car. The raft can be… a raft.

I think about this when working on design frameworks. Some modules will be more universally useful, while others will mostly address edge cases. A framework needs both; the question is which are taking up most of our time. My sense is we should devote more thought to the more universally useful modules, but it’s often the edge-case modules that require the most effort.

A follow-up post: What’s the Use of a Brick?