Vince Manze, president of program planning, scheduling and strategy at NBC, said the volume of reality on the schedule next year would be greater than usual. “Certainly some of it is strike-related,” Mr. Manze said. “But part of it is not. We always put reality on in the first quarter,” when shows like “Heroes” go on a brief hiatus, although he acknowledged that the volume of reality on the schedule for early next year was greater than usual.

Among the new reality offerings is “Oprah’s Big Give,” a contest on ABC sponsored by Oprah Winfrey to see who can give away large sums of money to society’s greatest benefit. ABC has long planned to have the series premiere in early 2008, but its potential effect on the network’s ratings is now more important than ever, given that the network’s most successful shows will be appearing in reruns.

Image Mark Walberg will be the host of The Moment of Truth on Fox, a reality show that is set to premiere in January. Credit... Joe Viles/Fox

At the other end of the spectrum is “American Gladiators” on NBC, a revival of a late-1980s competition that pits contestants against professional athletes in feats of strength, and “When Women Rule the World,” a Fox series that features male contestants trying to survive in an environment ruled by women.

Not all of the comedies and dramas in prime time will be repeats. Some returning series have long been scheduled to resume their run after the first of the year, including “Lost” on ABC and “Medium” on NBC. Some new series also had been set for premieres in January, including “Eli Stone” on ABC and “Terminator: The Sarah Connor Chronicles” on Fox. In addition, some continuing series have one or more individual episodes remaining, including most of the police dramas on CBS.

The deluge of new reality programming has become necessary because, in the weeks since the members of the Writers Guild of America stopped working on Nov. 5, nearly all comedy and drama series have shut down production for lack of new scripts. The writers are seeking a deal that will give them a share of the profits derived from the use of their material on the Internet and in other electronic media.