lego

Lego pieces of all varieties are part of a universal system. Despite variation in the design and purpose of individual pieces over the years, each remains compatible in some way with existing pieces. Lego bricks from 1958 still interlock with those made in the current time, and Lego sets for young children are compatible with those made for teenagers.

Bricks, beams, axles, gears, mini figures, and all other parts in the Lego system are manufactured to an exacting degree of precision. When snapped together, pieces must have just the right amount of strength and flexibility mixed together to stick together. They must stay together until pulled apart. They cannot be too easily pulled apart, or the resulting constructions would be unstable; they also cannot be too difficult to pull apart.