Node References and the Scene Tree

A script attached to one node very often needs to reach other nodes nearby in the scene tree, to read their state or call their methods.

extends CharacterBody2D

@onready var sprite = $Sprite2D
@onready var collision_shape = $CollisionShape2D

func _ready():
    sprite.modulate = Color.RED

$Sprite2D is shorthand for get_node("Sprite2D"), fetching a direct child node by name. @onready delays that lookup until the node has actually entered the scene tree, if you tried to grab $Sprite2D immediately when the script's variables are first declared, the child node might not exist yet.

Relative and absolute paths

var sibling = get_node("../Enemy")        # relative: up one level, then into Enemy
var anywhere = get_node("/root/Game/UI")  # absolute: from the very root of the tree

Relative paths (".." for parent, a name for a child) are more portable, since they don't break if the whole scene gets moved somewhere else in a larger tree, absolute paths are more explicit but brittle if the tree's structure changes.

Groups

For finding many unrelated nodes at once, node groups are usually cleaner than manual tree-walking:

# In the editor, add each enemy node to a group called "enemies"
for enemy in get_tree().get_nodes_in_group("enemies"):
    enemy.take_damage(10)

Groups decouple "find all the enemies" from the tree's exact shape entirely, new enemies just need to join the group, no code elsewhere needs to change.