Which of the following is not considered a gambling winning?

In the context of gambling winnings, the concept of games of chance involves various games where winning is primarily influenced by luck rather than skill. While money won from poker tournaments, winnings from slot machines, and prizes from lotteries are all classified as gambling winnings because they directly involve monetary prizes derived from risk and chance, games of chance as a category refers to the nature of the games themselves rather than the actual winnings.

Therefore, since the question specifically asks about what is not considered a gambling winning, identifying "games of chance" highlights the distinction between the types of games and the winnings associated with specific gambling outcomes. In summary, while "games of chance" is a broader category, it does not represent a specific form of winning, which makes it the correct answer to the question.