The Marvel No-Prize is a fake award given out by Marvel Comics to readers. Originally for those who spotted continuity errors in the comics, the current "No-Prizes" are given out for charitable works or other types of "meritorious service to the cause of Marveldom". As the No-Prize evolved, it was distinguished by its role in explaining away potential continuity errors. Initially awarded simply for identifying such errors, a No-Prize was later given only when a reader successfully explained why the continuity error was not an error at all.
The No-Prize, originally implemented in 1964, was inspired by the policies of many other comic book publishers of the time — namely, that if a fan found a continuity error in a comic and wrote a letter to the publisher of the comic, he or she would receive a prize of cash, free comics, or something similar.
When readers began pressuring Marvel to start giving out a similar prize,Stan Lee created the No-Prize — basically as a joke by the Marvel staff on the readers. In Fantastic Four #26, Lee ran a contest asking readers to send in their definition of what "the Marvel Age of Comics" really meant. As part of the letter, Lee wrote "there will be no prizes, and therefore, no losers". Originally, the "prize" was simply Lee publishing the letter and informing the letter-writer that he or she had won a No-Prize, which was actually nothing.
Other No-Prize contests asked readers questions and rewarded the most creative responses. For instance, one example asked readers for proof of whether the Sub-Mariner was a mutant or not. Winners had their letters printed along with Lee congratulating them on winning a No-Prize. When fans began demanding No-Prizes for no real reason, Lee took on a new approach. Since other comic companies had given out prizes for pointing out oversights and continuity errors in their books, Lee started doing the same thing, and awarded No-Prizes to people who found errors in the Marvel line of books — which at the time was quite a feat since Marvel was well known for its rigorous continuity.
The No-Prize soon evolved as a reward to those who performed "meritorious service to the cause of Marveldom": readers who first spotted a mistake, or came up with a plausible way to explain a mistake others spotted, or made some great suggestion or performed a service for Marvel in general.
The No-Prize had been intended as a reminder for Marvel readers to "lighten up" and read comics for pleasure rather than for prizes, or at least the thrill of being recognized for their efforts. However, letters soon tripled as fans wrote in looking for errors in every comic they could, and suddenly the non-existent prize was in high demand. In addition, many recipients of the "award" began to write Lee and ask why they had not received an actual prize.