Earlier this year, we saw the 60th anniversary of the original patent for the LEGO Brick being filed. There have been several other LEGO Bricks released in the meantime, designed for smaller hands.:
Duplo was first released as a toy for preschool children in 1969: it will turn 50 next year, in 2019. During the LEGO Group’s experimental phase in the early 2000’s, the line was rebadged ‘explore’, returning to the traditional ‘DUPLO’ branding in 2005.
Duplo Bricks are twice as large as the standard system bricks in all dimensions: 2x2x2=8 times the volume of a standard LEGO Brick.
Also pictured above are some samples of the QUATRO Brick. Produced from 2004 to 2006, these bricks are four times the volume of a standard system brick, with a 2×4 quarto brick occupying the same volume as 4x4x4=64 system bricks! Quatro also featured a couple of vehicles, and bricks with a curved edge (like the top of an arch.)