Creating smooth jump mechanics for platformer games

💡 Having trouble with jerky or unrealistic jumping? Need help with physics-based movement? 🚀 Get Help Now

JumpMaster_Dev

Posted on August 4, 2025 • Intermediate

🦘 Need help creating smooth jump mechanics

Hi everyone! I need an easy SMOOTH jump code I can use for my platformer games. The simple jump code I’m currently using is very jerky and doesn’t feel natural at all.

My current code just moves the character up and down with delays, but it looks terrible. I want something that feels realistic with proper physics. Any help would be greatly appreciated! 😊

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PhysicsMaster_Pro

Replied 30 minutes later • ⭐ Best Answer

Great question @JumpMaster_Dev! Smooth jumping is all about using velocity and gravity systems. Here’s how to create realistic, physics-based jumping:

🚀 Basic Smooth Jump System

First, create these variables: Y Velocity and Gravity

    when flag clicked
set [Gravity v] to [-1]
set [Y Velocity v] to [0]
forever
// Apply gravity
change [Y Velocity v] by (Gravity)

// Apply velocity to position
change y by (Y Velocity)

// Ground collision (adjust -170 to your ground level)
if <(y position) < [-170]> then
set y to [-170]
set [Y Velocity v] to [0]
end

// Jump input (only when on ground)
if <key [space v] pressed?> and <(Y Velocity) = [0]> then
set [Y Velocity v] to [15]
end
end

⚡ Advanced Jump with Ground Detection

For better collision detection with platform sprites:

    when flag clicked
set [Gravity v] to [-0.8]
set [Y Velocity v] to [0]
set [Jump Power v] to [12]
set [On Ground v] to [false]
forever
// Store old position
set [Old Y v] to (y position)

// Apply gravity when not on ground
if <not (On Ground)> then
change [Y Velocity v] by (Gravity)
else
set [Y Velocity v] to [0]
end

// Apply velocity
change y by (Y Velocity)

// Check ground collision
if <touching [Ground v]?> then
go to x: (x position) y: (Old Y)
set [On Ground v] to [true]
set [Y Velocity v] to [0]
else
set [On Ground v] to [false]
end

// Jump input
if <key [up arrow v] pressed?> and (On Ground) then
set [Y Velocity v] to (Jump Power)
set [On Ground v] to [false]
end
end

🎯 Variable Jump Height

Allow players to control jump height by holding the jump key:

    when flag clicked
set [Gravity v] to [-0.7]
set [Y Velocity v] to [0]
set [Jump Power v] to [14]
set [Jump Hold Time v] to [0]
forever
// Apply gravity
change [Y Velocity v] by (Gravity)

// Apply velocity
change y by (Y Velocity)

// Ground collision
if <touching [Ground v]?> then
repeat until <not <touching [Ground v]?>>
change y by [1]
end
change y by [-1]
set [Y Velocity v] to [0]
set [Jump Hold Time v] to [0]
end

// Jump start
if <key [space v] pressed?> and <(Y Velocity) = [0]> then
set [Y Velocity v] to (Jump Power)
end

// Variable jump height
if <key [space v] pressed?> and <(Y Velocity) > [0]> and <(Jump Hold Time) < [8]> then
change [Y Velocity v] by [0.5]
change [Jump Hold Time v] by [1]
end
end

🌟 Double Jump System

Add a second jump for more dynamic gameplay:

    when flag clicked
set [Gravity v] to [-0.8]
set [Y Velocity v] to [0]
set [Jump Count v] to [0]
set [Max Jumps v] to [2]
forever
// Apply gravity
change [Y Velocity v] by (Gravity)

// Apply velocity
change y by (Y Velocity)

// Ground collision
if <touching [Ground v]?> then
repeat until <not <touching [Ground v]?>>
change y by [1]
end
change y by [-1]
set [Y Velocity v] to [0]
set [Jump Count v] to [0]
end

// Jump input
if <key [space v] pressed?> and <(Jump Count) < (Max Jumps)> then
set [Y Velocity v] to [13]
change [Jump Count v] by [1]
wait [0.1] secs // Prevent multiple jumps from one press
end
end

💡 Pro Tips for Smooth Jumping

Adjust gravity value: Lower values (-0.5 to -1) feel more floaty, higher values (-1.2 to -2) feel heavier
Fine-tune jump power: Values between 10-18 work well for most games
Add coyote time: Allow jumping for a few frames after leaving a platform
Implement jump buffering: Register jump input slightly before landing
Use smaller gravity increments: Decimal values like -0.8 create smoother motion

Start with the basic system and gradually add features as needed. The key is finding the right balance of gravity and jump power for your game’s feel! 😊

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JumpMaster_Dev

Replied 1 hour later

@PhysicsMaster_Pro This is absolutely amazing! Thank you so much! 🎉

The basic smooth jump system works perfectly! My character now jumps with realistic physics instead of that jerky movement. The variable jump height is a great bonus too!

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GameTutor_Alex

Replied 2 hours later

Excellent tutorial! 🎮 Here are some additional enhancements you can add: