Guides Physics 2D Effectors Use PlatformEffector2D

Physics 2D Effectors 2 min read Updated Apr 2026

Use PlatformEffector2D

`PlatformEffector2D` is for one-way platform behavior.

Use it when the player should be able to move upward through a platform and then land on top of it.

If you want the editor workflow first, start with Create a 2D Effector in the Editor.

Good Fits

PlatformEffector2D is a strong fit for:

  • jump-through platformer ledges
  • floating platforms
  • layered traversal routes
  • levels where approach direction matters

What It Controls

  • Use One Way
  • Surface Buffer

That is enough for the classic rule:

  • pass upward through the platform
  • collide when landing from above

This page focuses on that core one-way platform workflow.

Scene Setup

  1. Create or select the platform object.
  2. Add a collider, usually BoxCollider2D.
  3. Add PlatformEffector2D.
  4. Leave Use One Way enabled.
  5. Tune Surface Buffer if the platform feels too strict or too loose.

Practical Example: A Jump-Through Ledge

For a simple platformer ledge:

  1. Add a BoxCollider2D to a narrow platform.
  2. Add PlatformEffector2D.
  3. Place the platform above the ground route.
  4. Jump up through it.
  5. Land on top of it from above.

If the character still feels like it catches the underside too aggressively, adjust Surface Buffer and test again.

If you want a small scene built for inspection, open:

samples/Platformer/Assets/Scenes/Effectors2D.scene.json

That sample includes a controllable probe, so you can jump through the platform, land on it from above, and compare it against the other 2D effector zones in the same walkthrough scene. The buoyancy section is also set up so you can swim upward and climb back out instead of getting trapped in the water.

How to Think About It

PlatformEffector2D changes how collisions are accepted.

It is not a movement script, and it is not a joint. That matters because the level designer can author the platform behavior directly on the platform object instead of pushing the whole burden into the player controller.

Recommended Use

Use PlatformEffector2D when the platform itself owns the rule.

That keeps the scene easier to reason about than trying to fake one-way platforms entirely from player-side collision code.

Related Guides