Cluedo was retitled because the traditional British board game "Ludo", on which the name is based, was less well known there than its American variant "Parcheesi." The North American versions of "Clue" also replace the character "Reverend Green" from the original "Cluedo" with "Mr. Green." This is the only region to continue to make such a change. Minor changes include "Miss Scarlett" with her name being spelt with one 't', the spanner being called a wrench, and the dagger renamed a knife. In the 2016 U.S. edition, the knife was changed to a dagger. And until 2003, the lead piping was
Cluedo wife, Elva Pratt (1913-1990), who had helped in designing the game, presented it to Waddingtons' executive, Norman Watson, who immediately purchased it and provided its trademark name of "Cluedo" (a play on "clue" and "Ludo"; "ludo" is Latin for "I play"). Although the patent was granted in 1947, due to post-war shortages in the UK the game was not officially launched by Waddingtons until 1949. It was simultaneously licensed to Parker Brothers in the US for publication, where it was renamed "Clue" along with other minor changes. There were several differences between the original game concept and that initially published