LEGO Supplementaries were sets released during the early days of the LEGO system. These sets were designed to supplement and expand upon the building possibilities of existing LEGO sets. Instead of being complete stand-alone models or kits, Supplementaries provided additional bricks, special parts, wheels, windows, doors, gears, or even motors. These sets were especially useful during an era when LEGO's product line was simpler and less specialized than it is today.
1977 LEGO Sets
1977 introduced the Expert Builder series—precursor to Technic—using beams, axles, and gears for mechanically rich models. Town-style sets broadened everyday subjects with houses, shops, and vehicles. Dedicated Space and Castle themes were still a year away, but elements and styling hinted at their imminent arrival.