[2020] Does Bethesda Even do the Math on their Game’s RNG?

Originally posted by International_XT

Funny, I just did a similar calculation.

I want a very specific Secret Service chest piece: Unyielding/AP refresh. Since there are 18 prefixes and 11 major modifiers, that means the odds of getting that exact roll are

1/18 * 1/11 = 1/198 = 0.5%

The likelihood p of getting this roll in one attempt is zero point five percent. Now, we can calculate the likelihood P of seeing this roll within N attempts by calculating the odds of not getting the roll after N attempts and subtracting from 1.

P(N) = 1-(1-p)^N

At least I think I got that right. Now, we can calculate how many attempts we need to get that likelihood down to at least 50%. Quick maffs later, we arrive at 139 attempts to get a 50% chance that one of those 139 rolls will be our desired roll. If we want a 75% chance of seeing our roll, we need to up that to 277 attempts.

(NOTE: I'm trying to be careful with the phrasing here because this is statistics and statistics often confuse people, including me. The above does NOT mean "after X attempts, the next attempt has a Y chance of being what you want"; it really means, "if you roll the dice X times, the odds of seeing the roll you want at least once among all of those rolls is Y.")

So now that we know that you need somewhere around 140 attempts for at least a decent chance to get your dream two star roll, we can calculate how long it'll take to get there.

Each Legendary Module costs 50 scrip, and the machine spits out 150 scrip per day, which means 3 modules per day. 140 divided by 3 is 47 days; that means if you grind out 150 scrip each day for over a month and a half, you have a coin flip's chance of getting your desired roll.

• For ONE armor piece.
  
• Assuming you get at least a two-star each time, which is NOT guaranteed, meaning the grind will likely take longer than this.

u/Ladydevann, this grind is crazy. Please do something about how people get endgame gear, because the current legendary system is insanely grindy and not very fun.