If you're tired of placing every single brick by hand, you probably need a roblox custom city generation script to handle the heavy lifting for you. Let's be honest, building a massive metropolis block by block is the fastest way to burn out on a project. I've spent way too many hours manually aligning skyscrapers only to realize the scale was off, and that's exactly why procedural generation is such a lifesaver in Roblox Studio.
Why go procedural anyway?
The biggest reason to use a script instead of manual building is variety. When you hand-build a city, you tend to get repetitive. You'll use the same three buildings over and over because, frankly, you're tired. A script doesn't get tired. It can take a pool of twenty different assets and shuffle them in ways you wouldn't have thought of, making the world feel much more organic.
Plus, there's the whole "infinite" factor. If you're making an open-world driving game or a survival sim, you might want a city that feels like it goes on forever. With a solid script, you can generate chunks of the city as the player moves, which is way more efficient than loading a giant, static map that tanks everyone's frame rate.
Setting up your building assets
Before you even touch a Script or a ModuleScript, you need stuff for the script to actually place. I usually start by creating a folder in ReplicatedStorage called "BuildingPool." Inside that, I'll drop a bunch of different models—shops, houses, tall offices, and maybe a park or two.
A pro tip here: make sure all your buildings have a consistent "PrimaryPart." Usually, this is a flat invisible part at the very bottom of the building. This makes it ten times easier for the script to align them to the ground. If your pivot points are all over the place, your city is going to look like a glitchy mess with buildings floating in the air or buried in the dirt.
The logic behind the grid
Most scripts rely on a grid system. Think of your map like a giant sheet of graph paper. Each square on that paper is a potential spot for a building. When you run your roblox custom city generation script, it basically loops through every "square" on that grid and decides what to put there.
You'll usually start with two nested loops—one for the X-axis and one for the Z-axis. It looks something like this in your head: "For every 50 studs on the X-axis, and every 50 studs on the Z-axis, pick a random building from my folder and clone it there."
Adding a bit of randomness
If you just tell the script to pick a random building, it's going to look okay, but maybe a bit chaotic. You don't want a 50-story skyscraper sitting right next to a tiny hot dog stand. That's where "weighting" comes in.
You can set up your script to check where it is on the map. If it's near the center (0,0), it should pick from the "TallBuildings" folder. If it's out toward the edges, it should stick to "SuburbanHouses." This gives your city a natural "downtown" feel without you having to manually place a single wall.
Dealing with roads and intersections
This is usually where people get stuck. Placing buildings is easy; connecting them with roads is the hard part. The simplest way to handle this in a roblox custom city generation script is to treat the road as just another "tile" in your grid.
Instead of just spawning buildings everywhere, you can tell the script: "Every third row should be a road." It sounds simple, but it creates a very structured, Manhattan-style grid layout. If you want something more complex like diagonal roads or winding paths, you're looking at much more advanced math, but for most Roblox games, a standard grid works perfectly and keeps the navigation simple for players.
Making the roads look right
Don't forget about orientation! A road running North-to-South needs to be rotated differently than one running East-to-West. Your script needs a little bit of logic to check its neighbors. "If there's a road to my left and a road below me, I should probably be a corner piece." It takes a little extra time to code, but it makes the city look professional instead of like a bunch of random parts thrown together.
Optimization: The silent killer
The biggest mistake I see when people start using a roblox custom city generation script is ignoring performance. If your script generates 5,000 buildings, and each building has 100 parts, you just added 500,000 parts to your game. That's a one-way ticket to Lag City.
To keep things smooth, you have to be smart. Use "StreamingEnabled" in your Workspace settings. This tells Roblox to only load the parts of the city that are near the player. Also, try to keep your building models as low-poly as possible. Use textures for windows instead of physical 3D glass parts. Your players' computers will thank you.
Adding the "lived-in" feel
Once the basic buildings and roads are spawning, the city can still feel a bit like a ghost town. To fix this, I like to add "clutter" logic to my scripts. This is basically a secondary pass where the script goes through and adds smaller details.
Think about things like: * Streetlights at every intersection. * Randomly placed trash cans or benches on the sidewalks. * Trees in the empty spaces between buildings. * Varying the colors of the buildings slightly so they don't all look identical.
These tiny details are what make a generated city feel like a real place rather than just a bunch of boxes. You can even use math.random to decide the height of each building, so even if you use the same model twice, one might be scaled slightly taller or shorter than the other.
Using Perlin Noise for better layouts
If you want to get really fancy, stop using math.random for everything and start using math.noise. This is called Perlin Noise, and it's how games like Minecraft generate their terrain.
Instead of total randomness, Perlin Noise gives you "smooth" randomness. You can use it to determine building height across your city. This creates natural "hills" of skyscrapers where the buildings get taller toward a certain point and then gradually taper off into smaller shops. It looks way more realistic than a jagged skyline where a shack is sitting next to a tower.
Wrapping it up
Building a roblox custom city generation script isn't just about writing code; it's about understanding how a city is put together. You start with the skeleton—the grid and the roads—and then you slowly add the skin and the guts.
It might take you a few days to get the logic feeling "right," but once it's done, you can generate a brand-new city in seconds. That's the beauty of it. You spend the time up front to save hundreds of hours later. So, grab some building assets, open up a new script, and start playing around with some loops. You'll be surprised at how quickly a few lines of code can turn a flat baseplate into a thriving metropolis.
Don't be afraid to break things, either. Some of my favorite map layouts came from accidental math errors that ended up looking cooler than what I originally planned! Keep iterating, keep optimizing, and most importantly, keep testing it with friends to see how it feels to actually run around in your automated creation.