(...) In the late 1950's LEGO introduced a line of vehicles and buildings at approximately 1:87 scale. We can guess that this scale was chosen to be compatible with many H0 train layouts. This was the original LEGO "SYSTEM OF PLAY". (URL) trains (...) (19 years ago, 16-Dec-05, to lugnet.general)
(...) Besides what Eric already explained, the classic Lego scale (Lego 1x2x3 classic door is 3 bricks tall) is 1:87. That scale was phased out between 1973-80, when first the 1x3x4 door came out (produced 1973-80). The minifig scale 1x4x5 door came (...) (19 years ago, 18-Dec-05, to lugnet.general)