Theme group

A theme group is LEGO's top-level categorisation under which multiple themes sit. It's a hierarchy:

• Theme group (top-level): e.g. "Action/Adventure"
• Theme: e.g. "Star Wars"
• Subtheme: e.g. "Ultimate Collector Series"
• Set: e.g. 75192 Millennium Falcon

The major theme groups

• Action/Adventure: licensed themes like Star Wars, Marvel, DC, Indiana Jones
• Licensed: all externally licensed themes (overlaps with others)
• Themed: LEGO's own themes — City, Ninjago, Friends
• Constraction: figure-building lines — Bionicle, Hero Factory (discontinued)
• Pre-school: DUPLO and LEGO Junior
• Adult: Icons, Architecture, Botanicals, Technic flagships
• Educational: LEGO Education, BOOST, Mindstorms
• Miscellaneous: anything that doesn't fit elsewhere — promotional sets, GWPs, polybags without a theme

Where Lakea uses this

On the /sets page you can filter by both theme group and theme. Theme group is broader; theme is more specific. We pull this structure from Brickset, where it's centrally maintained.