How do I implement stair stepping in Godot 3D?

After move_and_slide returns true for collision, raycast forward at foot height. If the hit is below max step height, raycast down to find the step top, and reposition the character there. Repeat until level.

Should I use ramp colliders or scripted stepping?

Ramp colliders are simpler and bug-free for grid-aligned stairs. Scripted stepping handles arbitrary stair shapes (spirals, broken geometry) but is more complex. Start with ramps; switch to script only if needed.

Fix: Godot 3D CharacterBody3D Falling Through Stairs

Q: Why does Godot CharacterBody3D fall through stairs?

Godot does not have built-in stair stepping like Unity's Step Offset. Place an invisible ramp collider over your visual stairs, or implement a step-up raycast in your movement code that snaps the character up small heights.

Quick answer: Godot has no built-in stair stepping. Place an invisible ramp collider over your visual stairs, or implement a step-up raycast in your _physics_process.

Here is how to fix Godot 4 CharacterBody3D characters that walk into stairs and refuse to climb. Godot does not include Unity-style Step Offset; you either model stairs as ramps under the hood or write the stepping logic yourself.

The Symptom

Character runs into a flight of stairs. Stops dead at the first step. Walking on flat ground works fine.

What Causes This

No built-in step support. CharacterBody3D treats steps as walls.

Slope angle too steep. An imaginary ramp through stair tops may exceed floor_max_angle.

Capsule shape catches lip. Even with a low slope, the capsule’s lower curve catches.

The Fix

Step 1: Add an invisible ramp collider over stairs. Create a StaticBody3D shaped as a ramp matching the stair slope. Disable the visual stairs’ collision (or set their CollisionShape3D disabled). The character glides up the ramp; players see steps.

Step 2: Or implement step-up logic.

extends CharacterBody3D

const MAX_STEP_HEIGHT := 0.4

func _physics_process(delta):
    # normal movement first
    move_and_slide()

    # detect blocked horizontal motion
    if get_slide_collision_count() > 0:
        var col = get_slide_collision(0)
        if col.get_normal().y < 0.5:   # nearly vertical wall
            try_step_up()

func try_step_up():
    var origin = global_position + Vector3.UP * MAX_STEP_HEIGHT
    var ahead = origin + transform.basis.z * 0.5
    var ray = PhysicsRayQueryParameters3D.create(ahead, ahead - Vector3.UP * MAX_STEP_HEIGHT * 2)
    var hit = get_world_3d().direct_space_state.intersect_ray(ray)
    if hit:
        global_position.y = hit.position.y + 0.01   # snap to step top

Step 3: Tune floor_max_angle.

floor_max_angle = deg_to_rad(50)   # default 45

Higher allows steeper ramps but also makes walls walkable; balance carefully.

Step 4: Use capsule collision shape. Sphere-bottom capsule rolls over stair lips better than a box.

Step 5: For competitive games, prefer ramp colliders. Ramp approach is deterministic and frame-rate independent. Scripted stepping can produce micro-pops between physics steps.

“Ramp under stairs for visual + physics separation. Or step-up raycast for arbitrary geometry. Pick by complexity.”

Related Issues

For 2D ghost collisions, see CharacterBody2D Ghost. For 3D velocity Y, see Velocity Y Zeroed.

Hide a ramp under the stairs. Or raycast and snap. Climbing works.