Setting up a roblox custom blacklist system script is one of those things you don't realize you need until your game starts getting a bit of traction and the "not-so-friendly" crowd shows up. If you've ever had a server ruined by someone being toxic or using exploits, you know exactly why having a way to permanently keep specific people out is a total lifesaver. While Roblox has its own built-in banning tools, they can sometimes feel a bit limited if you want to manage things across multiple experiences or have a really specific way of handling who gets the boot.
The beauty of making your own system is that you're in total control. You aren't just hitting a "ban" button and hoping for the best; you're building a persistent database of users who aren't welcome back, and you can even customize the message they see when they try to join. It makes your game feel more professional and, honestly, it gives you a lot of peace of mind as a developer.
Why Bother with a Custom Solution?
You might be wondering why you'd go through the trouble of scripting this yourself when you could just use the standard admin commands available in most kits. Well, the main reason is persistence and scale. Standard ban commands sometimes only work for the current server or rely on third-party systems that might go down or change their API. When you write your own roblox custom blacklist system script using DataStores, that list is yours forever. It lives in your game's data and works across every single server instance.
Another thing is the flexibility. Maybe you don't want to just ban someone; maybe you want to "shadow ban" them where they can play but can't interact with anyone, or maybe you want the ban to expire after exactly 48 hours. When you're the one writing the code, you can make those rules. It's also a great way to learn how DataStores work, which is a core skill for basically anything you'll ever do on Roblox.
The Logic Behind the Script
At its heart, a blacklist system is pretty simple. It usually follows a three-step process. First, whenever a player joins, the game needs to stop them at the door. Second, the script looks at the player's unique UserID and checks it against a list of "banned" IDs stored in a DataStore. Third, if a match is found, the script kicks them before they even have a chance to load their character or cause any trouble.
It's really important to use UserIDs rather than usernames. People change their usernames all the time, but that ID stays with them forever. If you ban "CoolGamer123" by name, they can just spend 1,000 Robux to change their name to "CoolGamer456" and walk right back into your game. If you ban ID 12345678, it doesn't matter what they call themselves; the script will still recognize them.
Setting Up the Basic Script
To get started, you'll want to put a Script inside ServerScriptService. This is where all the heavy lifting happens because you don't want the client (the player) to have any control over the blacklist logic. If you put it in a LocalScript, an exploiter could just disable it and bypass your ban.
Here's a rough idea of how the join-check logic looks:
```lua local DataStoreService = game:GetService("DataStoreService") local BlacklistStore = DataStoreService:GetDataStore("GlobalBlacklist")
game.Players.PlayerAdded:Connect(function(player) local userId = player.UserId local isBlacklisted = false
local success, result = pcall(function() return BlacklistStore:GetAsync("User-" .. userId) end) if success and result == true then player:Kick("You are blacklisted from this game. Appeal on our community server.") end end) ```
In this snippet, we're using a pcall (protected call). This is super important because DataStores are a web-based service. Sometimes Roblox's servers have a hiccup, and if you don't use a pcall, the whole script might break and let a banned player in by accident. This way, if the data check fails, we can handle it gracefully.
Adding an Admin Command to Manage the List
Having a list is great, but manually editing a DataStore through the console every time you want to ban someone is a massive pain. You really need a way to do it in-game. Most developers set up a simple chat command that only people with a certain rank (or the game owner) can use.
Imagine typing /blacklist 12345678 in the chat and having the player instantly removed and added to the database. It feels powerful, right? To do this, you'd hook into the Player.Chatted event and check if the person talking has permission. Then, you'd use SetAsync or UpdateAsync to save that player's ID to your DataStore.
One little tip: always make sure you have a "Whitelist" or "Unblacklist" command too. We all make mistakes, and there's nothing more awkward than accidentally banning your head moderator and having no easy way to let them back in!
Dealing with DataStore Limits
One thing you've got to keep in mind when working on your roblox custom blacklist system script is that Roblox limits how often you can ping their DataStore servers. If you have a huge game with thousands of people joining every minute, you can't just ask the DataStore "Is this guy banned?" every single time without potentially hitting a throttle limit.
A smart way to handle this is to keep a "cache" of the blacklist. When the server starts, it could grab the most recent list of banned IDs and keep them in a simple Lua table. Then, when a player joins, the script just checks that table—which is nearly instant—instead of asking the Roblox servers. You just have to make sure the table updates every now and then so new bans take effect in old servers.
Making the Kick Message Meaningful
Don't just use a generic "You were kicked" message. If someone is blacklisted, it's often helpful to tell them why or how they can fix it. You can store a "Reason" string alongside the boolean value in your DataStore.
Instead of just saving true, you could save a table like {IsBanned = true, Reason = "Exploiting", Admin = "Mod_Dave"}. When the player joins, your script pulls this table and kicks them with a message like: "Banned for: Exploiting by Admin: Mod_Dave." It adds a layer of transparency and helps your moderation team keep track of who did what.
Handling Alt Accounts
This is the hardest part of any moderation system on Roblox. If someone is dedicated to ruining your game, they'll just make a new account. While a roblox custom blacklist system script can't magically know that "NewAccount1" belongs to the same person as "BannedAccountA," there are some tricks you can use.
Some devs set a "minimum account age" requirement. If your account is less than three days old, you can't join. It won't stop everyone, but it makes it a lot more annoying for trolls to keep coming back. You can also look into more advanced methods like checking for specific hardware IDs, though Roblox is pretty strict about privacy, so your options there are a bit limited compared to standalone PC games.
Wrapping Things Up
Building your own blacklist system isn't just about being "the boss"; it's about protecting the community you're building. When players know that trolls get dealt with quickly and permanently, they're way more likely to stick around and actually enjoy what you've created.
It takes a little bit of time to get the logic right—especially making sure your DataStores don't fail—but it's a project that pays off almost immediately. Once you have a solid roblox custom blacklist system script running in the background, you can spend less time worrying about moderators and more time actually making your game fun. Just remember to keep your admin permissions tight, use UserIDs instead of names, and always have a backup plan for when things go wrong!