Building a roblox raycasting script gun is one of those "aha!" moments for every developer. If you've been messing around in Roblox Studio for a while, you've probably tried using physical projectiles—those little spheres with Velocity—and realized they can be a bit of a nightmare when it comes to lag or high-speed combat. Raycasting is the industry-standard solution. It's fast, it's precise, and once you get the hang of it, it's actually way simpler than trying to manage a hundred physics-based bullets flying around a map.
When we talk about a "hitscan" weapon, we're essentially talking about raycasting. Instead of waiting for a part to physically touch a player, the game draws an invisible line the split-second you click. If that line intersects with a part, the game registers a hit. It's how games like Phantom Forces or Counter-Strike feel so snappy. In this guide, we're going to break down how to put one together without losing your mind over vector math.
Why Raycasting Beats Projectiles Every Time
Let's be real: physical bullets look cool because you can see them travel through the air. But in a multiplayer environment, they're messy. You've got to worry about the bullet's "Touch" event firing correctly, network ownership, and the fact that a fast-moving bullet might literally skip over a thin wall between two frames.
A roblox raycasting script gun solves all of that. It calculates the entire path of the bullet instantly. There's no "skipping" because the math happens all at once. If you want that visual "bullet travel" look, you can always add a decorative tracer afterward, but the actual logic—the part that decides if you got the kill—is handled by the raycast. It's much lighter on the server and feels way more responsive to the player.
The Foundation: Origin and Direction
To make a raycast work, you need two main pieces of information: where the ray starts and where it's going. In Roblox, this is usually the tip of your gun (the "Muzzle") and the position of the player's mouse.
The tricky part for beginners is often the math behind the direction. You can't just tell the script "shoot at the mouse." You have to calculate a Vector3 that represents the distance and direction from the gun's tip to the target. It looks something like this: (MousePosition - MuzzlePosition).Unit * Range.
The .Unit part is important because it turns that direction into a "normalized" vector (a length of 1), which you then multiply by your gun's range (say, 500 studs). This gives you a consistent line regardless of how close or far the mouse actually is.
Setting Up Your RaycastParams
Before you fire that ray, you have to tell it what to ignore. This is where RaycastParams comes in. If you don't use this, your gun might accidentally hit the player firing it or the gun's own barrel. Nothing is more frustrating than clicking to shoot and having the bullet "hit" your own arm.
You'll want to create a new RaycastParams object and add the player's character to the FilterDescendantsInstances list. Set the FilterType to Enum.RaycastFilterType.Exclude. Now, your ray will pass right through the shooter like they're a ghost, only stopping when it hits the environment or an enemy.
The Server-Client Handshake
This is where things get a bit more complex. You can't handle the whole roblox raycasting script gun on the client side. If you do, hackers will have a field day. They could just tell the game "Hey, I hit everyone on the map at once," and your game would believe them.
The workflow should look like this: 1. Client (LocalScript): Detects the mouse click, calculates the target position, and sends a signal to the server via a RemoteEvent. 2. Server (Script): Receives the signal, performs its own raycast to verify the shot, and then subtracts health from the victim.
Wait, why does the server do the raycast again? Because the server is the source of truth. It checks if the shot was even possible. If a player tries to shoot through a brick wall that shouldn't be shoot-through, the server's raycast will hit the wall first, and the "damage" command will never execute. It's a basic but effective way to keep things fair.
Writing the Core Logic
When you actually call workspace:Raycast(origin, direction, params), Roblox returns a RaycastResult. This object is gold. It contains: * Instance: What did we hit? (A head? A wall? A tree?) * Position: Exactly where in 3D space did the impact happen? * Normal: Which way is the surface of the object facing? (Great for placing bullet holes!) * Material: Is it wood? Stone? Plastic? (Perfect for choosing the right "clink" sound effect.)
If the result is nil, it means the player missed or the target was out of range. If it's not nil, you can check if the Instance is part of a Model with a Humanoid. If it is—boom—you've got a successful hit.
Making It Look "Juicy"
A raw raycast is invisible. If you stop at the logic, your gun will feel like a "delete button" rather than a weapon. You need visual feedback.
To make it look like a real roblox raycasting script gun, you should use Beams or Trails for tracers. When the ray hits a wall, spawn a small "Impact" particle effect. Play a "bang" sound on the server so everyone else can hear the shot, and maybe a "ping" sound on the client to give the player that sweet dopamine hit for landing a shot.
One pro tip: don't make the tracer perfectly instant. Even though the raycast is instant, the visual line can "travel" slightly over 0.05 seconds to give the eye something to track. It makes the gun feel much more physical and less like a laser pointer.
Handling the "Wait, I Hit Him!" Lag
In a perfect world, the server and client would see the same thing at the same time. In reality, ping is a thing. If a player shoots at a moving target, the target might have already moved on the server's screen.
To fix this, many high-end Roblox games use "lag compensation." This involves the server looking back in time to see where the enemy was when the player clicked. However, if you're just starting out, don't worry about this too much. A standard server-side raycast is usually "good enough" for most casual games. Just keep in mind that if players complain about shots not registering, ping is usually the culprit.
Common Mistakes to Avoid
- Ignoring the Gun Tip: Don't start the ray from the player's camera. While it makes aiming easier, it allows players to shoot around corners while their character is completely hidden. Start the ray from the gun's barrel.
- Forgetting to Use Task.Wait(): If you have a fully automatic gun, don't use
wait(). Usetask.wait(). It's more precise and optimized for the modern Roblox engine. - No Debounce: Always include a "cooldown" on the server. If a player fires a RemoteEvent 500 times a second using a cheat engine, your server-side script should be smart enough to say, "Hold on, this gun only fires 10 rounds per second."
Wrapping Up
Creating a solid roblox raycasting script gun is a rite of passage. It teaches you about vectors, client-server communication, and game feel. It might take a few tries to get the RaycastParams right or to make the tracer look smooth, but the result is a weapon system that is robust, professional, and scalable.
Once you've mastered the basic hitscan gun, you can start adding the fancy stuff: wall penetration, headshot multipliers, or even ricochets by using the Normal property of the RaycastResult to bounce a second ray off a surface. The possibilities are pretty much endless once you stop thinking in "parts" and start thinking in "rays." Happy scripting!