Drop rate in gaming is the number of times a monster is likely to yield particular items when defeated by players. During the calculation of a drop rate, you divide the number of items you obtained by the total number of times you defeated or killed the particular monster. Basically, every item has the probability to be dropped. The likelihood of being dropped when expressed as a number is called the drop rate of that item. Nevertheless, the drop rate of an item isn’t necessarily a guarantee that it will drop. For instance, a “1 in 3” drop rate that necessarily means this particular item will drop after every third kill.
The number of kills you make doesn’t necessarily increase your drop rate. As such, each kill doesn’t do anything to improve your chances. This is a popular misconception among video game players who base their assumptions on the belief that killing a monster ‘n’ times should make your drop rate 1/n. This is popularly or otherwise called the gambler’s fallacy. The truth remains that nothing is guaranteed you, irrespective of how many times you kill your monster. Therefore, the chances of getting an item anytime you kill the monster always remain unchanged – constant. Hence, functions of probability do not consider additions either do they include past occurrences.
After experience a couple of incidences where nothing drops after several kills, one can only conclude that these incidences are very unlikely, but still possible. This is why unlikely occurrences are always observed even in-game levels just as real life. Similarly, this unlikeliness of the drop rate doesn’t guarantee any future luck. Chances cannot be added. This is why when your drop is 5% in 50 kills, it isn’t 10% in 100 kills. Hence, the talk about ‘good’ or ‘bad luck’ which some players often express during gameplay is purely a psychological sentiment.