LEGO 1955 / System i Leg Sets

System i Leg, which translates to System of Play, was the natural progress of LEGO Mursten and is the foundation of L:EGO sets today. Designed by Godtfred Kirk Christiansen who organized the existing LEGO Mursten sets and modeled new designs around a single, common theme - a townscape or street scene. After nearly a year of development the result was the LEGO Mursten System i Leg (System of Play). The System i Leg was unveiled at the Nürnburg Toy Fair in February 1955. The original Automatic Binding Bricks sets and then LEGO Mursten sets were continued to be manufactured under the System i Leg theme.

1955 LEGO Sets

1955 marked the debut of the LEGO System i Leg—“System of Play”—the foundation of the modern LEGO philosophy. Introduced at the Nuremberg Toy Fair, the concept unified LEGO sets under a single scale and theme: a buildable town with houses, vehicles, and streets. Though early reception was cautious, it established the guiding Principles of Play later adopted companywide. LEGO also entered new markets in Sweden and Germany, broadening its reach beyond Scandinavia.