Unity Input System: the setup order that avoids dead input

Start with actions, not keys

The new Input System works best when you describe meaningful game actions—move, jump, interact—instead of hard-coding individual keys. The same action can then be bound to a keyboard, gamepad, or touch control.

Unity recommends an action-based workflow. This guide uses one ownership model for a single-player prototype: PlayerInput manages that player's actions. In local multiplayer, each PlayerInput can use its own action copy, so the example does not mix in a reference to the original Action Asset.

A minimal setup order

Begin with one Action Asset and the one intended PlayerInput component. An accidental second input handler can duplicate calls in a single-player scene, while multiple PlayerInput components are valid in a deliberate local-multiplayer setup.

1. Install the Input System package, enable the new backend in Active Input Handling, and restart the Editor when prompted.
2. Create a Gameplay Action Map and set Move to Action Type Value and Control Type Vector2. In Move's add-binding (+) menu, choose Add Up/Down/Left/Right Composite, then set each Path to Up=W, Down=S, Left=A, Right=D. To use arrow keys, assign the matching key to each direction instead. A plain Add Binding connecting one key directly to Move is not the same setup.
3. Set Jump to Action Type Button and use a plain Add Binding for Space. Use Save Asset when Auto-Save is off. Add PlayerInput to the player object, attach the Action Asset, and set the Default Action Map to Gameplay.
4. Read this player's Move action from PlayerInput.actions instead of the original asset. The example below reads only Move; binding Space does not implement jumping.

using UnityEngine;
using UnityEngine.InputSystem;

[RequireComponent(typeof(PlayerInput))]
public class MoveProbe : MonoBehaviour
{
    private InputAction move;

    private void Awake()
    {
        PlayerInput playerInput = GetComponent<PlayerInput>();
        move = playerInput.actions.FindAction("Gameplay/Move", true);
    }

    private void Update()
    {
        Vector2 direction = move.ReadValue<Vector2>();
        transform.Translate(new Vector3(direction.x, 0f, direction.y) * Time.deltaTime);
    }
}

Four checks when input stays silent

Before rewriting a script, check whether Default Action Map is assigned, the Gameplay map is active, the Game view owns focus, and the single-player scene has no accidental second PlayerInput.

Reading device state directly can be useful for a quick prototype, but an action-first structure is easier to extend to rebinding and multiple devices.