Getting a roblox custom climbing system script to feel right is honestly one of the hardest things to nail in Studio, but it makes a massive difference in how a game actually plays. If you've ever tried to make an adventure game or an obby that feels a bit more modern, you've probably realized that the default Roblox "ladder" mechanic is pretty lackluster. It's stiff, it only works on specific parts, and it doesn't give you that fluid, cinematic feel you see in games like Uncharted or even some of the high-end parkour experiences on the platform.
The thing is, the default movement system is designed to be a catch-all for every game. It's reliable, sure, but it's not exactly exciting. When you decide to write your own script for climbing, you're basically taking control away from the built-in physics engine and telling the character exactly how to behave when they're near a vertical surface. It sounds intimidating, but once you break it down into raycasts and state management, it starts to make a lot more sense.
Why move away from the default ladder?
The biggest issue with the standard setup is that it's binary. You're either on a ladder or you aren't. There's no middle ground for grabbing onto a ledge, shimmying across a pipe, or leaping between handholds. If you want a character to actually look like they're putting effort into a climb, you need a system that can detect the specific geometry of a wall and align the player's body to it.
A custom system also lets you handle animations way better. With the default system, the climbing animation just loops regardless of your speed or the surface you're on. With a roblox custom climbing system script, you can sync the hand movements to the actual distance traveled, or even use Inverse Kinematics (IK) to make sure the character's hands are actually touching the bricks they're supposedly climbing. It's that level of polish that separates a "work in progress" from a finished game.
The core logic: Raycasting is your best friend
Everything starts with raycasting. If you aren't familiar, think of a raycast as an invisible laser beam shot out from a point in space to see if it hits anything. To make a climbing system work, you're constantly shooting these "lasers" out from the front of the player's HumanoidRootPart.
You'll usually want at least two rays: one at chest height and one at head height. If the chest ray hits a wall but the head ray doesn't, you know you've found a ledge. If both hit, you're looking at a flat wall. This is the foundation of the script. The script needs to check these hits every frame (or at least very frequently) while the player is in the air or moving toward a wall.
The tricky part is filtering. You don't want the player climbing on invisible walls, NPCs, or small pebbles on the ground. You have to use RaycastParams to make sure the script only cares about parts that are actually marked as "climbable." I usually use a specific Tag (using CollectionService) or just check the name of the part, though tags are definitely the cleaner way to go.
Handling the State Change
Once your raycast confirms that there's a wall in front of the player, you have to change the player's state. By default, Roblox humanoids like to be in "Falling," "Running," or "Jumping" states. To make your custom script work without the physics engine fighting you, you'll often want to set the Humanoid's state to Physics or just anchor the HumanoidRootPart and handle the movement yourself via CFrame.
I personally prefer using LinearVelocity or VectorForce objects because they keep the movement feeling "physical." If you just teleport the player (CFrame manipulation) every frame, it can look a bit jittery, especially if the player has a high ping. Using modern physics constraints allows the engine to smooth things out for you.
When the player is in the "climbing" mode, you also have to disable their normal movement keys. You don't want them accidentally walking "forward" through the wall. Instead, you map the W and S keys to move the character up and down the Y-axis of the wall's surface.
Making the movement feel fluid
A common mistake I see in many roblox custom climbing system script versions is that they feel too "snappy." You hit a wall and bam, you're stuck to it like a magnet. Real movement has momentum. You should probably add a tiny bit of a "lunge" when the player first grabs the wall.
Another thing to consider is how the player turns corners. If you're climbing a square pillar, what happens when you reach the edge? A really good script will cast rays sideways to see if the wall continues around a bend. If it does, you can rotate the player's CFrame smoothly to follow the contour. It's a lot of math—mostly involving Cross Products and Dot Products—but it's what makes a system feel professional.
Don't forget about the "letting go" part, either. Players should be able to jump off the wall. When they hit the jump button, you want to apply a force that pushes them away from the wall and upward, rather than just letting them drop straight down. It feels way more natural and allows for that cool wall-to-wall jumping style.
The importance of animations and IK
You can have the most mathematically perfect script in the world, but if the character is just T-posing while sliding up a wall, it's going to look broken. You need a solid set of animations: an idle hang, a vertical climb, and a horizontal shimmy.
But even with great animations, characters have different heights and limb lengths. This is where Inverse Kinematics (IK) comes in. Roblox has some built-in IKControls now that make this way easier than it used to be. You can set the target for the character's hands to the exact point where the raycast hit the wall. This way, if the wall is slightly uneven, the hands actually reach out and "touch" the surface. It prevents that annoying clipping where the hands disappear into the brick or hover two inches away from it.
Optimizing for performance
Since a roblox custom climbing system script usually runs on the RenderStepped or Heartbeat signal, you have to be careful about performance. Running ten raycasts every single frame for every player in a 50-person server will eventually cause some lag if you aren't smart about it.
Keep the logic on the client (LocalScript) as much as possible for the actual movement. The server doesn't need to know the exact millisecond-by-millisecond position of a climbing player; it just needs to know the general state so it can replicate the animations to other people. You should also make sure the script "sleeps" when the player is nowhere near a wall. There's no point in checking for ledges if the player is standing in the middle of a flat desert. A simple distance check or a broad-phase overlap check can save a lot of CPU cycles.
Dealing with bugs and edge cases
Expect things to break. It's just part of the process. One of the most common bugs is the "vibrating player," where the script can't decide if the player is on the wall or off the wall, so it toggles between states fifty times a second. You can fix this by adding a small "cooldown" or a "buffer distance." Don't let the player regrab the same wall for a few frames after they've let go.
Another weird one is the "wall clipping" issue. Sometimes, if the move speed is too high, the player will get pushed inside the part. Always include a "safety" raycast that checks if the player's head is inside a solid object and pushes them back out if necessary.
Building a roblox custom climbing system script is definitely a bit of a rabbit hole. You start by just wanting to climb a wall, and suddenly you're learning about vector math and procedural animation. But honestly, that's the fun of it. Once you get that first smooth transition from a run to a jump to a ledge-grab, you'll realize it was totally worth the headache. It changes the whole vibe of the game and gives the player so much more freedom to explore the world you've built.