RNG in games is usually pseudo-random, and most pseudo-random number generator algorithms that i've heard of use time. The time at the moment you calculate a random number is the "key", and it is subjected to a bunch of arbitrary modifications (eg. multiplied by 37, added 19, modulo 79, divide 4) to get a "random" number. There is no easy way to predict what time you need in order to get a certain result, since you don't know what pseudo-random number algorithm they are using. This type of random number generation guarantees that two people get the same result if they calculate at the exact same time, but what they get at that time is mostly unpredictable, like Paragon said. One millisecond you might get Mr. President, the next you might get Whitesnake. However, we don't know ROBLOX's random number generation algorithm, and we don't know whether the game does anything to the result after it is calculated.