In Scrabble, one of the most popular board games of all time, players use tiles with letters on them to spell out words on a grid, crossword-puzzle style. The idea is so clear and simple that you'd think some sage would have dreamed it up in antiquity. But in fact, the game originated in the 1930s, when an unemployed architect named Alfred Mosher Butts passed the time by creating a new word game.

Butts' inspiration was to combine the vocabulary skills required for crossword puzzles and anagrams with the additional element of chance. The methodical inventor studied the front page of The New York Times, and tabulated how often each of the alphabet's 26 letters were used. (Among other things, he discovered that vowels appear far more often than consonants, and that the vowel "E" was the most frequently used of all.) Based upon letters' frequency, he assigned different point values to them, concocted some simple rules, and then used his architectural drafting equipment to draw a board for a game that he initially called Lexico and then Criss-Cross Words, before he took on a partner, entrepreneur James Brunot, who helped him come up with a catchier moniker, Scrabble [source: Hasbro].

The game's enduring appeal is that while its concept is easy to understand, it's challenging to play because coming up with word combinations from a random assortment of letter tiles requires both intellectual agility and a big vocabulary. According to a 2004 New York Times article on the Scrabble subculture, the game's elite -- the 100 or so top tournament players -- have working vocabularies in excess of 120,000 words, which is three to four times that of the typical college graduate. As one top player noted in the article: "You can't really compete at the top level without knowing every word between two and nine letters" [source: Smith].