Four panelists must determine guests' occupations - and, in the case of famous guests, while blindfolded, their identity - by asking only "yes" or "no" questions.

Contestants with unusual occupations were interviewed by the panelists. Only questions that could be answered with a "yes" or "no" were allowed. At the conclusion of the questioning, the panelists attempted to guess the contestants occupation. There was also a "mystery guest", usually a famous person; the panelists had to wear masks when questioning this person and the guest usually disguised his/her voice.—J.E. McKillop <[email protected]>

The original version of the all-time classic panel game, which produced 876 shows between 1950 and 1967. Four celebrity panelists tried to determine, through questioning, the occupation of the contestant. The panelists could only ask questions that could be answered yes, no or similar answer, with the contestant winning $5 per "no" answer. The game ended either upon 10 "no" answers, a panelist correctly guessing the player's secret or at the discretion of the moderator. Usually but not always, the last segment saw the now-blindfolded panelists attempt to determine the identity of a mystery guest, who always disguised his voice in an attempt to avoid being identified. For many years, the regular panelists of Arlene Francis, Dorothy Kilgallen and Bennett Cerf were welcome visitors in many homes during the 10:30 p.m. EST Sunday "What's My Line?" airing; a fourth seat was used for guest panelists, though that seat, too, was filled by regulars including Steve Allen (who left for other TV projects) and Fred Allen (who died in 1956) through the years. After Kilgallen's 1965 death, her seat, too, was filled by a guest panelist. Host Daly was reserved as the emergency mystery guest, but was never needed; he would serve as the scheduled mystery guest for the show's final CBS airing in September 1967. "What's My Line?" was updated for syndication in 1968, with new host Wally Bruner (later Larry Blyden). Longtime Arlene Francis returned for the new version, along with newcomer Soupy Sales; Bennett Cerf also made frequent visits until his 1971 death. A 1975 special, "'What's My Line?' at 25," recalled some of the best moments from the CBS series. "What's My Line?" remains one of TV's most fondly remembered game shows and currently airs as part of Game Show Network's Black and White Overnight programming block. At one point, CBS and Pearson TV planned a new version of "What's My Line," with a new celebrity panel but with the same rules; however, those plans never came to fruition.—Brian Rathjen <[email protected]>