Why does my Jump action fire twice on a single press?

You subscribed in OnEnable and didn't unsubscribe in OnDisable, then OnEnable ran again. Each subscribe stacks. Or you have both PlayerInput SendMessages and a C# event subscription, both wired to the same handler.

What's the right subscription pattern?

Subscribe in OnEnable, unsubscribe in OnDisable. Pair them. Cache the action reference and unsubscribe the same delegate you subscribed.

Why do PlayerInput's modes affect this?

PlayerInput Behavior dropdown chooses how it dispatches. SendMessages calls OnJump on every MonoBehaviour. Invoke C# Events fires UnityEvents on the actions. If you also manually subscribe via action.performed +=, you double-fire.

Fix: Unity Input Action Performed Fires Twice on Press

Quick answer: Subscribe in OnEnable, unsubscribe in OnDisable. Pick one PlayerInput Behavior (SendMessages OR Invoke C# Events OR Invoke Unity Events) and don’t mix it with manual action.performed +=.

Press Jump once. Player jumps twice. Two callbacks are subscribed to the same action.

The Symptom

Single key press triggers double action. Worsens after scene reloads (more subscriptions stack). Logging the handler shows it called N times where N is the number of times OnEnable ran.

The Fix

public class Player : MonoBehaviour
{
    public InputActionAsset actions;
    private InputAction _jump;

    void Awake()
    {
        _jump = actions.FindAction("Jump");
    }

    void OnEnable()
    {
        _jump.performed += OnJump;
        _jump.Enable();
    }

    void OnDisable()
    {
        _jump.performed -= OnJump;
        _jump.Disable();
    }

    void OnJump(InputAction.CallbackContext _) { /* jump */ }
}

OnEnable subscribes; OnDisable unsubscribes. Stable count of one subscription per active instance.

PlayerInput Behavior Picks One

If you use the PlayerInput component:

SendMessages: defines OnJump(InputValue) on the script.
Invoke Unity Events: wire UnityEvents in the inspector.
Invoke C# Events: subscribe to playerInput.actions["Jump"].performed in code.

Pick one. Don’t both define OnJump and subscribe action.performed.

Verifying

Add Debug.Log in OnJump. Press once. Should log once. Reload the scene 5x; still logs once per press.

“Pair OnEnable + OnDisable. Pick one Behavior. No double-fire.”

Related Issues

For rebind handler leak, see rebind leak. For control scheme switch, see control scheme.

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