LEGO operates to tighter manufacturing tolerances than the Swiss aerospace industry. That is not a marketing claim, it is a documented fact. Every brick snaps together with the same satisfying click it has had since 1958, and the DUPLO size makes it safe from 18 months. If there is one building toy worth buying, it is this one, because every set you add integrates perfectly with every set before it, indefinitely.

LEGO DUPLO · Age 18m+
Classic Brick Box (120 pieces)
The foundational building set. 120 bricks, storage box, compatible with every DUPLO set made since 1969. Teaches creative thinking, not just assembly.
Check price at AmazonOpen-ended over themed
We recommend the Classic Brick Box over themed sets for early childhood. Themed sets (trains, farms, fire stations) limit the imagination to a single narrative. A box of assorted bricks with no instructions teaches children to create rather than replicate. Add themed sets later, but start open-ended.
The 120-piece set is a solid foundation, but be realistic: most children exhaust its possibilities by their second birthday. The 190-piece set (around £55) is the better buy if budget allows, the additional pieces make significantly more complex structures possible and extend the toy’s life considerably.
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