The LEGO Basic theme, which began in the 1970s, was designed to be a more general, non-thematic series of sets. Unlike the themed sets that revolve around specific stories, characters, or concepts (e.g., space, city, or pirates), the Basic theme provided a collection of standard LEGO bricks and pieces, often in a variety of colors. The goal was to encourage free building and creativity without the confines of a specific theme or narrative.
1984 LEGO Sets
In 1984, LEGO expanded two of its most popular themes, LEGO Space and LEGO Castle, introducing new subthemes that added depth and variety to the LEGO play experience.