Adult Fan of LEGO®. The most common term used to refer to LEGO® fans who are adults.


Billund, Denmark. Headquarters and primary design center for The LEGO® Group.


A universal name for a LEGO® piece, regardless of shape or color.


A LEGO® fan whose primary interest is building MOCs.


Construction toys “compatible” with LEGO® created and sold at lower cost, designed to compete with LEGO® brand building bricks. Often used to specifically denote brands which infringe upon copyright/trademark (to distinguish from legal competitors). Considered off-limits by most LEGO® fans.


A LEGO® fan whose primary interest is collecting official sets.

Dark Ages

A period in a LEGO® fan’s life when he or she sets aside LEGO® in favor of school, dating, motor vehicles, or other non-LEGO® pursuits.


A universal name for a LEGO® piece.


The list of LEGO elements that are included in an official LEGO® set.


LEGO Digital Designer. The LEGO® Company’s official program for designing digital LEGO® models.


A highly sophisticated interlocking brick system. Also a children’s toy played with by many adults.


Oh no you didn’t! Technically, the official plural form for more than one element of LEGO® is “LEGO® brand building bricks”. That’s ridiculous, though, so most LEGO® fans refer to one or more bricks as “LEGO®”, following the grammatical convention of “fish” and “sheep.”


Short for Minifigure. The blocky miniature figures featured in most LEGO® sets.


The thin, curved figures featured in LEGO® Disney Princess, Elves, and Friends themes.


My Own Creation. Any LEGO® creation designed and built by a LEGO® fan without instructions. Generally pronounced “mock” (not “Em-Oh-Cee”)


Any LEGO® piece which is 1/3 the height of a brick.


Short for Signature Minifig. The minifigure version of a LEGO® fan that he or she uses in online communities as an avatar. Sigfigs may or may not resemble the person physically, as LEGO® fans used to interacting with each other online often discover at LEGO® conventions.


Studs Not On Top. A building technique that places LEGO® elements on their sides or even upside down to achieve the shape or structure the builder wants in their creation.


Sticker Across Multiple Pieces. A dreaded situation where a set’s instructions require a sticker to be placed across several pieces, ensuring the pieces can never be separated without ruining the sticker.


The distinct cylindrical bump or knob on the surface of LEGO® bricks and serves as one half of the mechanism by which pieces interlock.


Any LEGO® plate which is devoid of all or most studs, giving it a smooth upper surface.

Adapted from The Brothers Brick, see more at