Jump Up

Part of the Input and Movement section of Coddy's Godot journey. Lesson 13 of 28.

To jump, set velocity.y to a big upward speed in the frame the player presses jump. Up is less y, so the number is negative:

var jump_velocity = -500

func _physics_process(delta):
	velocity.y += gravity * delta
	if Input.is_action_just_pressed("jump"):
		velocity.y = jump_velocity
	move_and_slide()

You do not code the way down. Gravity keeps adding to velocity.y, so the hero slows as it rises, stops at the top and falls back.

Use is_action_just_pressed, not is_action_pressed. A held key would set the speed to -500 every frame, and the hero would fly off the screen.

Challenge

Easy

Make the hero jump.

Between the gravity line and move_and_slide(), add an if for Input.is_action_just_pressed("jump").
Inside it, set velocity.y to jump_velocity.

Press Play and press Space: the hero jumps and lands again, and holding Space does not make it fly. Then Check.

Try it yourself

extends CharacterBody2D

var gravity = 1000
var jump_velocity = -500

func _physics_process(delta):
	velocity.y += gravity * delta
	move_and_slide()

All lessons in Input and Movement

1Input Actions

Press to Move Left and Right One Axis Four Directions Just Pressed Unhandled Input

4Smooth Movement

Speed Up Slowly Friction Face the Way You Move Clamp to the Screen Clamp Both Axes

2CharacterBody2D

CharacterBody2D Walk With Velocity Walls Stop You Walk Everywhere Fair Diagonals

5Project: Platformer Hero

Hero: Run Hero: Jump

Hero: Smooth Run

Hero: Face the Way

Hero: Back to the Start

Hero: Reach the Ledge

3Gravity and Jumping

Fall With GravityJump UpOnly From the Floor Run and Jump Variable Jump Double Jump

Practice on your own: Godot playground