Hosts:
NBC (1974-75):
The game begins with a "Target" number being selected at random (ex.: $575). After it is set, a multiplier from 5 to 50 is randomly chosen (in this case, let's say 35) to create a Super Jackpot amount (in this case, $20,125, and BTW, if the Target amount was $995 and the multiplier was 50, they would "cheat"; instead of $49,750, the Super Jackpot would be worth $50,000!).
After this has been set, $100 is placed in the Jackpot to start it off, and the game begins. The "expert" calls on one of the other fifteen players, who first reveals the value of his/her riddle (each one is worth a different amount), which is then added to the Jackpot, and then reads it (ex.: "I'm the animal whose name sounds like it has laryngitis. What animal am I?").
If the Expert answers the riddle (in this case, "a horse") correctly, s/he selects another contestant and continues; if s/he answers incorrectly, s/he trades places with the player who stumped him/her.
In any case, play continues as follows until the "Jackpot" riddle comes up (since the show's inception, it was customary for the player who had the Jackpot riddle to yell "JACKPOT!!" when s/he was called on). When this comes up, the Expert may either answer it, or continue answering riddles (and risk losing his/her "Expert" status). If the Expert chooses to answer the Jackpot riddle and answers it correctly, s/he splits the money with the player who posed it and retains his/her "Expert" status for the next round. If the Expert's answer is incorrect, however, s/he trades places with the other player, and the Jackpot amount is carried over to the next round.
During the course of the game, if the Jackpot amount (or its last 3 digits) match the Target amount, the contestant has a chance to try for the Super Jackpot; the riddle asked for it was a special one posed by Geoff, which was first asked to the last player to pose a riddle, and if s/he answered it incorrectly, the Expert would be given a chance. If either player answered correctly, the Expert and the player who posed the riddle split the money in the Super Jackpot. In any case, right or wrong, the game continues as before.
NOTE: For the last 13 weeks of the NBC run, the Target was dropped, and the Super Jackpot was established randomly, without a multiplier; it could be worth anywhere from $2,000 to $10,000. Also, instead of riddles, straight general-knowledge questions were asked. When the Jackpot question was found, the Expert could either try to answer it, or go for the Super Jackpot by answering all remaining questions in the game, including the Jackpot question. If the player missed the Super Jackpot question, the Jackpot was wiped out, so it was hard to build a Jackpot. If, however, the Jackpot question was the last one found, the Super Jackpot was discarded.
NOTES:
The random-number generator which set the Super Jackpot "multiplier" on the NBC version went through some interesting changes:
Originally, each number from 5 to 50 had an equal chance of being selected; this resulted in a number of uncomfortably high Super Jackpots early on, so it was changed to two each of the numbers 5, 10, and 15, and one each of the rest. However, this didn't sit well with the viewers (who had grown accustomed to the large Super Jackpots so prevalent in those early days), so it was changed once more, this time to two each for the numbers 15 and 20, and one each of the rest.