This article is from the alt.usage.english FAQ, by Mark Israel misrael@scripps.edu with numerous contributions by others.
does NOT mean "The metal template has been molded." It's what
Julius Caesar said on crossing the river Rubicon to invade Italy in
49 B.C. The "die" is a gambling die, and "cast" means thrown. The
phrase means "An irrevocable decision has been made." (The Latin
words, "Jacta alea est", are given in Suetonius' "Divus Julius",
XXXII. "Alea" denotes the *game* of dice, rather than the physical
die: the dice game is in its thrown state. "The die is cast" and
"the dice are cast" would be equally good translations. Compare
"Les jeux sont faits", heard at Monte Carlo.)
Plutarch wrote two accounts in Greek of Caesar's crossing the
Rubicon. Both times, he gives the words as "Anerriphtho: kubos" =
"Let the die be cast." In one of the accounts (Life of Pompey), he
says that Caesar actually uttered the words in Greek; in the other
(Life of Caesar), he suggests that the words were already a proverb
before Caesar uttered them.
 
Continue to: