# Godot Collision Debugging Basics

Find why game objects pass through, stick, or never trigger collisions.

## Outcome
Debug a small collision problem without rewriting the whole player controller.

## Safe first step
Turn on visible collision shapes before changing physics code.

## Ladder steps
### 1. Show collision shapes
Learn to show collision shapes as one discrete move in the project path.

Check: You can explain or demonstrate: show collision shapes.

### 2. Check body type
Learn to check body type as one discrete move in the project path.

Check: You can explain or demonstrate: check body type.

### 3. Check layer and mask
Learn to check layer and mask as one discrete move in the project path.

Check: You can explain or demonstrate: check layer and mask.

### 4. Create one tiny test scene
Learn to create one tiny test scene as one discrete move in the project path.

Check: You can explain or demonstrate: create one tiny test scene.

## Examples
### Practice debug -> visible collision shapes
```sh
Debug -> Visible Collision Shapes
```
Expected signal: A visible result you can compare before moving on

### Practice inspect collisionlayer
```sh
Inspect CollisionLayer
```
Expected signal: A visible result you can compare before moving on

### Practice inspect collisionmask
```sh
Inspect CollisionMask
```
Expected signal: A visible result you can compare before moving on

## Common traps
- Changing movement code before proving shapes overlap.
- Confusing Area signals with physics body movement.
- Using production art to debug collision size.

## Practice task
Create a small practice case for godot collision debugging basics and write what each step proves before moving to the next one.

## Next steps
- Download the Obsidian note.
- Review the Anki cards.
- Pick one related ladder and do the practice task.

## Related
- [Browse topic clusters](/topics/)
- [All learning ladders](/learn/)