Random Encounters

Lich Van Winkle posted about random encounters pre-D&D:

Hexmaps and Random Encounters before D&D

I have a love-hate relationship with random encounters. On one hand, they do add spice and a cost for dilly-dallying. On the other hand, it's a lot of encounters to prepare and not necessarily use. They've provided great fun in my Cold Fens and Lost City of D'Abo sub-locations and occasional fun in Felltower, too.

I'm very interested in how they may have come about.