If you've ever played Garry's Mod, you know exactly why a roblox physics gun script is one of the coolest things you can add to a sandbox game. There is something incredibly satisfying about clicking on a random crate, watching a neon beam snap to it, and then being able to suspend it in mid-air or launch it into the horizon. It's a staple for any game that focuses on building, chaos, or just general messing around with the engine's physics.
Creating one might seem like a nightmare involving high-level math, but it's actually more about understanding how Roblox handles "ownership" of parts and how constraints work. You aren't just moving a part; you're telling the game engine to ignore gravity for a second and follow your mouse. Let's break down how to actually build one that doesn't feel clunky or laggy.
Why use a physics gun anyway?
Most games let you click a button to interact with things, but a physics gun gives the player a lot more agency. Instead of just "Open Door" or "Push Button," you give them the power to reorganize the world. In the context of Roblox, this is great for sandbox builders or even puzzle games where you need to move blocks to reach a higher platform.
The magic happens when you combine the roblox physics gun script with the engine's built-in solver. You don't have to manually calculate the trajectory of a falling object. You just set the position, and the engine handles the collisions, the momentum, and the weight. It makes the game feel "meaty" and interactive.
The core logic behind the script
Before you start typing away in Studio, you need to understand the two main ways people handle these scripts.
The first way is the "Old School" method, which uses BodyPosition and BodyGyro. These are technically deprecated now, but honestly, a lot of people still use them because they're super easy to wrap your head around. They essentially act like invisible rubber bands pulling an object toward a target point.
The second way, and the one I'd recommend for a modern game, is using AlignPosition and AlignOrientation. These are newer constraints that are much more stable. They allow you to move an object to your mouse's position while keeping it steady, and they play much nicer with the current physics engine.
Handling the Client and Server divide
One thing that trips up a lot of new scripters is the concept of Network Ownership. If you try to move a part purely through a LocalScript, it might look fine on your screen, but to everyone else in the game, that crate is still sitting on the ground.
To make a roblox physics gun script work properly, you have to use a RemoteEvent. When the player clicks, the client tells the server, "Hey, I want to pick this up." The server then checks if that's allowed and, most importantly, sets the Network Owner of that part to the player. This makes the movement feel smooth as butter because the player's computer is now the one doing the heavy lifting for that specific object's physics.
Setting up the Tool and Raycasting
You'll want to start with a basic Tool object in your starter pack. Inside that tool, you'll need a handle (obviously) and a LocalScript. The first job of this script is to figure out what the player is actually looking at.
We do this through Raycasting. When you click, the script shoots an invisible line from your camera into the 3D world. If that line hits a part, we've found our target. You'll want to filter out things like the baseplate or the player's own character, otherwise, you might accidentally try to pick up the floor or yourself, which usually ends in a hilarious but frustrating physics explosion.
The Beam Visuals
A physics gun doesn't feel right without a visual beam. Using a Beam object or even just a stretched Part works well here. You want one attachment at the tip of your gun and another attachment that gets created at the point where you grabbed the object. It gives the player that visual feedback that they are actually "holding" something.
I'm a big fan of using a bright neon color for this—something like Cyan or Electric Purple—to really lean into that sci-fi aesthetic. You can even animate the texture of the beam to make it look like energy is flowing through it.
Making the movement feel smooth
Once you've got the part attached to your mouse via a constraint, you'll notice a problem: it might be too snappy. If the part instantly teleports to your mouse position, it looks robotic. To get that "floaty" physics gun feel, you need to tweak the Responsiveness property of your AlignPosition.
If you set the responsiveness a bit lower, the object will have a tiny bit of weight and lag behind the mouse. This is actually a good thing! it makes the object feel like it has mass. If you're moving a giant heavy boulder, it should feel a bit harder to swing around than a tiny plastic chair.
Rotating the object
A good roblox physics gun script isn't just for dragging; it should let you rotate stuff too. Most scripts use the scroll wheel or specific keys (like R and T) to rotate the object while it's held.
You can do this by updating the CFrame of the target attachment. Basically, while the player is holding the key, you slowly change the orientation values. Because we are using an AlignOrientation constraint, the part will naturally spin to match the new rotation we're feeding it. It's way smoother than just snapping the part to a new angle.
Dealing with common glitches
Let's be real, physics in Roblox can get weird. If you've ever seen a part start vibrating violently until it flies into the sun, you've experienced a physics glitch.
One way to prevent this in your script is to disable collisions between the object and the player while it's being held. If the object you're holding bumps into your own character, the physics engine tries to push both things away from each other. This creates a feedback loop that usually results in the player being launched across the map. By using CollisionGroups, you can make it so the held object just passes through the player, saving everyone a lot of headaches.
Another tip: always set a distance limit. You don't want players picking up a building from across the map. Check the distance between the player's character and the hit position of the raycast. if it's more than, say, 50 studs, just don't let the script trigger.
Security and Exploits
Because the server is giving the player network ownership of a part, you have to be a bit careful. A malicious player could potentially use their own exploits to move that part anywhere they want once they have ownership.
While you can't perfectly stop everything, you can add server-side checks. For example, the server can constantly check if the part is moving way faster than it should be. If the part is suddenly moving at 5000 miles per hour, the server should probably step in and reset its velocity or take away the player's ownership.
Final touches to make it "Pop"
If you really want your roblox physics gun script to stand out, add some sound effects. A low hum while holding an object or a "clack" sound when the beam connects makes a massive difference in how the tool feels.
You could also add a "Throw" mechanic. When the player lets go of the click, instead of just dropping the part, you can apply an Impulse to it. This lets players hurl objects at each other, which—let's be honest—is the main reason anyone uses a physics gun in the first place.
Building a script like this is a fantastic way to learn how Roblox handles the relationship between the client and the server. It's a bit of a "right of passage" for scripters. Once you get the hang of moving parts around with constraints, you'll find that those same skills apply to making vehicles, drones, or even complex boss mechanics. So, get into Studio, start messing with some AlignPosition constraints, and see what kind of chaos you can create!