Users tend to think software is malfunctioning if the same number is randomly generated at an "unnaturally" high frequency. But if each event is independent, there may be nothing wrong with the software; it may just be a low probability event. In playing a game like roulette, this error in intuition is called the gambler's fallacy.

If the main purpose of a program is to meet a user's expectations, then it may be worth taking the gambler's fallacy into account. In other words, it may be worth lowering the probability of a number being generated twice in a row.

For something like a flashcard game, it likely makes sense to take the gambler's fallacy into account so users are exposed to each card before repeating any. But, when trying to maximize fairness between players, the question is much more murky.