The contestant selects a grocery item and must determine whether the price given for it is either the current price ("now") or the price as of the specified past date ("then"). To win the game, the contestant must correctly guess three items that are on adjacent wedges of the circle. The contestant may continue selecting as many items as needed until the goal is either achieved or made impossible.
There is an unstated rule that there are always four "now" prices and two "then" prices. Also, there is usually one product that is clearly marked "NEW!" which means that the product is obviously a "now" price.

Until 1986, the game was named "Now....and Then." The name was changed to more accurately reflect the decision the contestant had to make.
The "then" prices are researched by Kathy Greco who uses archived newspaper advertisements as her source. 