Programming Rarity is Harder Than You Think 

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No. You just don’t implement rarity. You only want to make it as if there is rarity but in reality you will only get common items, and then you make a button to get legendary with robux.

The downside of this method is that the legendary isn’t a 1% chance but in fact a 0.25% chance because of the random selection of the loop then the random number selection.

funnily enough, i made a rarity system using this concept in obby creator like 3 years ago without even realizing this is how rarity systems work in roblox coding

Actually, tbh, I agree with you. Rarity is harder than I think. Haven't had to program rarity before. The closest I got was programing a sort of 'fairness' system in randomizing maps. (1 in a row, and 2 in a row.)

I tried to make a rarity in a different project in a different language, and I gave up, decided to use a simple formula to decide the chance of each rarity. It's not perfect but it gets the job done.

I had a system for my now abandoned game. The rarity system was so advanced. It had to take like 8 values in mind when generating. It was basically an armour generator. Where each piece had multiple stats. But certain stats where handled differently. Before i started it, i thought it was gonna be super easy. shit was harder than anything ive done. It also had to work with data saving. I had like 5d array for each stat. Crazy. It used like 5 scripts in total. the rarity script was like 300+ lines. And when i code, i code to make it as efficient as possible. Then i realised, its roblox. It doesnt need to be this complicated. So now i stick to simpler games.

When you’re using the counter variable while looping through the rarities, this is called prefix sums, and it’s pretty useful for cases like these. But I would say that it’s better to just construct the prefix sums table right after your rarities table is initialized so that you can have faster runtime (especially if there is a lot of rarities).

ByteBlox: "Let me talk about todays sponsor" Me: *exits fullscreen to leave video* ByteBlox "Being me" Me: *enters fullscreen again*

Subscribed. You do some really interesting games, and scripts. Since I'm into programming (and will be doing it as my future job and in my T-Level at college), you've inspired me to start programming in lua again. Thank you.

i saw the text "programming rarity is harder than you think" no its not i made a system right after i saw it to show and it was easy . for all devs that struggle : if you struggle with a rarity system , dont give up (BTW : If something is 1% of 100 % in 1000 drops i got ONLY 9 of them)

I know practically nothing about programming even though I'm a bit interested in it, I've never focused on studying it, but I find it very comfortable to watch videos of programmers (more specifically people programming on roblox) teaching mechanics and explaining the codes and how they work.

the way i made a rarity system is more focused on convenience of updating, so instead of making a table or list of rarities i just made a folder containing numberValues and effects of each rarities, so it picks a random number between the lowest and whatever the sum of all values are (all of which are handled by a "ipairs" sequence), which was NOT easy.. but saved me a lot more time adding more and more stuff on it

I always thought there were basic frameworks that most roblox game devs use to implement somewhat usable rarity systems, depending on the amount of effort the devs put into the game would directly correspond to how well and unique the rarity system would be (If they change the framework that is).

This video inspired me to make a program to prove that Programming Rarity is NOT Harder Than You Think. I was able to make a PHP program that uses less than 50 lines of code and achieved the goal of implementing a rarity system

Some people are so lazy at doing that and just give you common all the time There's no way to get a higher rarity no matter what like, there is a game i played i dont remember what but its a gacha that spins and lets you see all the things, i manage to land it on legendary but then it switched the pointer to a common like, they didn't even try to hide it, it's so obvious that they dont want you to get it cuz the spin is slow when it landed to legendary but then it did a quick spin that perfectly lands to the common.

To simplify his system just add ahatever numbers you want and get a loop to count all the numbers meaning the number will be from 1 to any number u want like 157 and it will still work but just have different %

Being this early is criminial.. also ur vids r really good.. keep up the good work!!

Quitting gambling is pretty hard too.

"Guys RNG's take effort I promise!!!!"

Oh yeah ByteBlox, thank you! You changed my life you opened my eyes! Y- you saved everything that was going wrong in my life!!!

I programmed rarity in a card game i made, i sorted differente rarities (common, rare, super rare) gave them values, then sorted a random integer between 1-100, depending on witch number it gave some rarity was sorted, then inside that rarity was an array of cards, it randomly choose one of them, that way i could have multiple rarities and many cards inside each rarity, worked perfectly

When it says “0.5% chance” you actually just make it a 2% chance so it makes your players feel more lucky and get a gambling addiction

this is late but for randomNum u shld do local randomNum = Random.new():NextNumber(0, 100) instead this selects numbers with decimals for randomNum as well and not just whole ones, so that you can add rarities with decimals like .5 if you're a psychopath please pin if u see this

You can use your rarity "weight" as the maximum range for math.random and then a successful pull is when your random number is equal to 1. This makes it so you don't have to hand modify your weights every time you decide to add something rarer because adding something rarer just means the new entry will have a bigger weight number.

How to make the rarity system better? The simple answer is including a crafting system to make the lesser valued items still useable and important. I don't even care about those thousands of reskinned collectable Pets from BIG Games. Like what is the point? Nostalgia is such a sneaky trap to keep players playing your game.

As a game developer there's several ways around this. Well I use unreal engine so it might be different for Roblox.

taking statistics made it easier honestly

all you need is knowing basic statistics and use random numbers

The only thing the pet sim kids are growing up to be are gambling addicts lol

Yo just an idea but could you use multiple random number generators to find rarity so you don’t need to make it up to 100 percent? For example:find random int from 1 in 100. If you don’t get 1, roll 1 in 50. If that fails roll 1 in 10. If they get 1 on any of these rarities then they get the pet associated with that rarity. Then you can have things like 1 in 1 billion without having to worry about any of the math, and if they fail all rolls you can just give them the lowest rarity. This also makes it a lot easier to add 2x luck mechanics etc, even if it’s a bit slow computational wise with too many rarities

i dont code at all, but you made this video interesting so i wanna support you

bro you are amazing! I have been trying to understand this for a while.

I gave up coding in Unity. this actually looks a lot more easier than c#👍 *gets a severe mental breakdown* *destroys laptop*

Oh my glorious king ByteBlox are you going to do the thug shaker i have been waiting for so long

Please make a tutorial on how to level up your Scriptingan I have been stuck on third tomoe for a year now

nah i was forced to watch a 1 min ad, great vid tho!

Made a rarity system with pity and guarantee, and let me tell you man, it wasn't fun.

can i use this: i am new so dont make fun please local luckforcommon = 60 local luckforrare = 39 local luck for legendary = 1 local pull = math.random if pull = 61 then print("rare") elseif pull > 99 or pull = 100 then print("ooga")

you don't need to make your rarity weights total up to 100, but instead just do math.random(1, [sum of all your weights]) for your random number instead of 1 - 100.

5:14 that module function is like a struct or class i think so is it?.it seems similar thats why i asked

NoNoNo programming a rarity isn't hard but programming a good rarity is hard

if table order is not waranteed then dont return a value at that point. Instead, store the value and keep iterating

Imagine doing this and then figuring out there is Math.Random 💀💀💀

I am pretty sure that sols rng devs don't try to loop through 1 billion

I had to make an item that gives you one of 7 items with equal odds, plus one that has a 2% chance of spawning I did it by putting all of them except the rare item in a table, then I made a random number generator that picks a number from 1 to 100, if the result is above 98 then it picks the rare item, else it picks one of the random common items

all other devs after watching: 💀🤡 math.random(), random.new()

rarity is easy. just select a random index in an array and make lots of copies of common and one copy of legendary. the method in this video doesnt have the chances completely correct

I can make a rarity system, but I don't know how to do it in roblox

Only if i would be willing to learn this instead of being lazy 😅😅 i got a realy trash mental when it comes to time consuming things.

rarity. random number gen: 0-1000 common 0-800 rare 801-950 epic 951-980 legendary 981-1000 easy.

sol's rng devs explaining why they wasted more than 5 minutes on their game:

pls make an RNG game where the better rarity you have, the better you are than everyone, for example if you have a better rarity you might be faster or get weapons or maybe even admin powers

THX YOU VERY MUCH. ME AND MY FRIEND CAN FINALLY MAKE A GAME

Take notes Setro..

been considering for the course

Came expecting a detailed lecture about lua randomness and how to make your system truly random, got a beginner’s tutorial.

Idk I think coding rarity is pretty easy lol I can think of the code off the top of my head.

Bro rarity system is super easy, i have done it before in the past without watching a video abt it, what you have talking about

surely you can pick a random number between 1 and 100 and then do if then statements comparing them to the rarity numbers? this seems more complicated

Me be like: local number = math.random(1,100) if number == 1 then print(YOU UNLOCKED THE 1 PERCENT OMG OMG OMG!!!!!!)

What software are you using to code this in?

I remembre, i maked a Weight Module in your discord server before i get banned for a stupide reason

proof that sols rng is underrated!!!!11!11!1!1!1!!!!1!

damn we can put table on table on table

that feels kinda icky even tho you got a 1 on the random number you only have a 1/4 chance of actually getting the legendary

How to code to get epic every 10 pulls ? Oh and pity system 😅

Saw the title Here is the code: import random rarities = ["legendary", "rare", "uncommon","common"] chances= [5, 20, 30, 45] result = random.choices(rarities, chances) print(result) quit() Harder than I think? doubt so

You are a lost cause if you genuinely think this is remotely advanced.

Now I get why you think coding this is hard, and I agree.

what about just taking a random number, between 1-100, then if it is greater or equal to 100, it is legendary, elif it is greater or equal to 85 it is epic and so on?

Nah this too confusing ☠️

Cant u just do: Local numb= Math.random(1,100) If numb 60 and numb < 85 then Rarity = uncommen Elseif numb >85 and numb

*This is my script, but it keeps giving me Common and I cant fix it* local Background = script.Parent.Background local Title = Background.Title local RarityText = Title.RarityText Background.Visible = false local ChanceList = { ["Common"] = {360000, Color3.fromRGB(38, 236, 94)}, ["Rare"] = {29979 , Color3.fromRGB(41, 129, 236)}, ["Epic"] = {1001, Color3.fromRGB(140, 30, 162)}, ["Legendary"] = {200, Color3.fromRGB(162, 153, 24)}, ["Nebulous"] = {120, Color3.fromRGB(96, 45, 200)}, ["Spectral"] = {100, Color3.fromRGB(170, 176, 200)}, ["SUS"] = {90, Color3.fromRGB(200, 114, 74)}, ["Mystic"] = {69, Color3.fromRGB(200, 36, 93)}, ["Universal"] = {50, Color3.fromRGB(125, 127, 200)}, ["Sapphire"] = {39, Color3.fromRGB(102, 0, 204)}, ["Galactic"] = {20, Color3.fromRGB(157, 160, 184)}, ["FluxFlare"] = {10, Color3.fromRGB(119, 204, 204)}, ["Electric"] = {5, Color3.fromRGB(54, 147, 181)}, ["Clockwork"] = {3, Color3.fromRGB(255, 204, 102)}, --{"Lucky", "Gamepass", Color3.fromRGB(0, 255, 21)}, --{"Owner", "THE OWNER 👑", Color3.fromRGB(255, 140, 0)} } local displayedChances = { ["Common"] = {3, Color3.fromRGB(38, 236, 94)}, ["Rare"] = {5, Color3.fromRGB(41, 129, 236)}, ["Epic"] = {10, Color3.fromRGB(140, 30, 162)}, ["Legendary"] = {20, Color3.fromRGB(162, 153, 24)}, ["Nebulous"] = {39, Color3.fromRGB(96, 45, 200)}, ["Spectral"] = {50, Color3.fromRGB(170, 176, 200)}, ["SUS"] = {69, Color3.fromRGB(200, 114, 74)}, ["Mystic"] = {90, Color3.fromRGB(200, 36, 93)}, ["Universal"] = {100, Color3.fromRGB(125, 127, 200)}, ["Sapphire"] = {120, Color3.fromRGB(102, 0, 204)}, ["Galactic"] = {200, Color3.fromRGB(157, 160, 184)}, ["FluxFlare"] = {1001, Color3.fromRGB(119, 204, 204)}, ["Electric"] = {29979, Color3.fromRGB(54, 147, 181)}, ["Clockwork"] = {360000, Color3.fromRGB(255, 204, 102)}, --{"Lucky", "Gamepass", Color3.fromRGB(0, 255, 21)}, --{"Owner", "THE OWNER 👑", Color3.fromRGB(255, 140, 0)} } local remoteEvent = game:GetService("ReplicatedStorage").DonationDone local spinsLeft = 12 local function spinRarity() local randomNum = math.random(1, 391686) -- Change 391686 to the SUM of all rarities (since the chosen rarity must be the appropriate % of the total rarities) local counter = 0 if spinsLeft > 0 then local selectedColor -- local selectedIndex local name for rarity, items in ChanceList do print(rarity, items[1]) counter += items[1] if randomNum

wouldn't "math.randomseed(os.time()) local random_number = math.random(1, 100) if random_number

me when i use "pick random from 1 to 100" in scratch:

1:26 yes, replicatedstorage

me when math.random

For those who understand the code but don't understand how the system works, and why, here's an explanation: Let's say your rarity weights are: {"common" = 60, "rare" = 20, "legendary" = 1}. The total weight is 81 (60 + 20 + 1). Imagine a number line from 1 to 81. The "common" rarity "owns" the range from 1 to 60 (its weight). The "rare" rarity "owns" the range from 61 to 80 (weight of common + weight of rare). The "legendary" rarity "owns" the last spot (81). If the random number is 35, it falls within the range owned by "common" (1 to 60) and thus "common" is chosen. By accumulating weight, we create a system where the random number effectively "lands" on a specific portion of the line based on the weight distribution, ensuring each rarity has the intended chance of being chosen.

Bro you arrived in a great time, I just got to roblox lua scripting and these videos are teaching me better than my courses lol

short answer: chatgpt, long answer: this video edit: thanks though, i understood the video

Ngl I worked this out on my own when I was learning to code, the title is a massive overstatement.

rarity while seeming initially hard isnt that bad when you get around to understanding tables, so i decided id program a simple lua weighted randomizer and send it here for people to reference if they manage to see this comment first we wanna start off with a table, which is essentially a list. However, each list is only really allowed to have one entry within each line, so to make things more optimized we are effectively putting a small list containing the NAME of the item, as well as its rarity. the rarity in question acts more as a 'frequency' meaning the higher the number, the more abundant the object would become. the template is essentially {(brick color),(frequency)} afterwards we are going to run code that makes a new table (list), that inserts each entry of the original table (list) the number of times of its frequency. Meaning the white brick in the situation (view below) would be written down on the list 100 times. We do this for every entry and effectively have a long imaginary list with 230 entries (in the situation im showing off below.) The final part of this is picking a random number from 1 to the number of entries we have, and just taking the object from the spot in the list! ------------------------- local OurExampleList = { {"White Brick",100}; -- common {"Purple Brick",70}; -- Uncommon {"Green Brick",50}; -- rare {"Orange Brick",10}; -- legendary i guess } local ImaginaryList = {} --imaginary list that is used for later to decide which specific brick we want by inserting the (total of) 230 possibilities into for CurrentIndex, CurrentListEntry in OurExampleList do for count =1,CurrentListEntry[2] do --see the [2]? This is important here because we are sorting through the original example list, which has mini lists and we want the rarities from the mini lists. CurrentListEntry is also technically one of these, which can be found from the CurrentIndex (meaning the mini list {"White Brick",100} is found when CurrentIndex is at 1) table.insert(ImaginaryList,CurrentListEntry[1]) -- places the current entry into the imaginary list, this is run as many times as its frequency end end local Result = ImaginaryList[math.random(1,#ImaginaryList)] --This is another index similar to [2], but we are picking a random entry, from 1 (the first entry) to the TOTAL number of entries (which is essentially 230) print(Result) ------------------------- sorry for lack of formatting or if I was to vague on any topics, but this is just some simple sample code that is a nice stepping stone to understanding absolute essentials to development

Ah he used chatgpt for this

1:26 "ReplicatedStorage"

I recently began my first game and just so happen to need this rn and u happen to upload this only 4 days ago wow how lucky am i to stumble upon this video thank u 🙏

Thank you for this. And to all the viewers here, there's multiple variants of weighted RNG, I would highly recommend to try things out such as making an alternative to math.random(), or find another way to calculate the result. It's a complex system and there's no system that suits all, experiment with it. And with such, another method to this video is to add up all the weight values and multiplying it math.random() with nothing in the parentheses; from there, you go through each weight again and remove it from the accumulated weight that you got from multiplying till you reach 0 or less and return the item that triggered that check. However, by doing this method, you may see that high rarities will appear to be more common depending on the weight you assigned. Again, I highly recommend you to try things out and find new ways; step a little out of your comfort zone, but not by too much, learn from the behaviors and mistakes you come across.

As a RNG game developer, I can explain how games add new items with new rarities not adding up to 100% while still being accurate. A first idea I had was to make, for example, common (50%) be added 50x in a table, and all that for each of the rarities, then returning a random one, except that's way too slow for huge numbers like 1,000,000, Roblox risks to crash. But then the ultimate solution is quite quite hard to understand : developers just use a rarity table like in this video, except their random generator function computes each "part"'s rarity weight and return a random part on its weight compared to other ones. Yep, that's quite hard to understand and redo but that's how it works. I spent hours documenting that subject and I made a pretty accurate rng system.

Meanwhile python

Why the counter variable? I was with you fully until you added that, which just seems unnecessarily complex and harder to implement.

I'm no expert but in python id use randint to generate and intiger from 1-100 then put those values to be a random item (For example, if the intiger is 1-80 its commonn, if I get 81-90, its rare, etc.)

Yaay i luv being weak and insignificant!.. Such a bottom!!.. //>w

4 mins this time lol still good luck tho i dont even have notifications on i just hoped on my home page lol

roblox devs are on crack if they think rarity is hard wait till yall learn about quaternians

Do your weights even matter here? Because if it doesn’t go through the table in order the rarities are just completely different to the weights you’ve set

Don’t know anything about scripting but this video was entertaining

scripting a rarity system is easy tbh, the real difficulty is scripting a LUCK system inside the rarity one

Idk in roblox studio, but in unity i would just make the machine chose a random int between 1 and a 100, and if its 1 &&

i've made a rarity system before and it worked pretty well, i'll try explain it a bit simply here. pretty much have a list of things with a rarity e.g. if its 1 in 1000 make its chance 1000 times all the chances together and this is your weight or totalVal now theres 2 methods i use to expand from this: 1. less complicated but you simply get a random number, sort the list of rarities from rarest to most common, and check if the random number is less than or equal to the (totalVal / chance) 2. allows for multiple rarities of the same chance, because with 1. you can only have something like 1 in 1000 once for example, first you have to create a lowerBound variable and another variable "currentLowest" for example which starts at 0 , for each rarity you set its lowerBound var to currentLowest + 1, and then you create another variable "higherBound" for the rarity, which is set to (currentLowest + totalVal / chance), at last you create the random num and check for each rarity if the number is between the lowerbound or higherbound rarity sorry if this seems all complicated but i kind of just wrote this from the top of my head, hope this helps anyone oh P.S, you'll need to use Random:NextInteger rather than math.random because math.random can't handle large numbers, which can become a problem when multiplying multiple rarites for the total val

Is this actually 1% chance on legendary? I think it's even less? The way you retrieve the object makes me a little confused on the actual percentage. Also this method brings me a lot of memories about greedy programming problems, like the backpack greedy problem.