By 1954, Christiansen's son, Godtfred, had become the junior managing director of the Lego Group. It was his conversation with an overseas buyer that led to the idea of a toy system. Godtfred saw the immense potential in Lego bricks to become a system for creative play, but the bricks still had some problems from a technical standpoint: their locking ability was limited and they were not versatile. In 1958, the modern brick design was developed; it took five years to find the right material for it, ABS (acrylonitrile butadiene styrene) polymer. The modern Lego brick design was patented on 28 January 1958.
Since around 2000, the Lego Group has been promoting "Lego Serious Play", a form of business consultancy fostering creative thinking, in which team members build metaphors of their organizational identities and experiences using Lego bricks. Participants work through imaginary scenarios using visual three-dimensional Lego constructions, imaginatively exploring possibilities in a serious form of play.