UI.Selectable.interactable.
#pragma strict
// required when using UI elements in scripts
public class Example {
    public var startButton;
    public var playersReady;
    function Update() {
        // checks if the players are ready and if the start button is useable
        if (playersReady == true && startButton.interactable == false) {
            //allows the start button to be used
            startButton.interactable = true;
        }
    }
}
using UnityEngine; using System.Collections; using UnityEngine.UI; // required when using UI elements in scripts
public class Example : MonoBehaviour { public Button startButton; public bool playersReady;
void Update() { // checks if the players are ready and if the start button is useable if (playersReady == true && startButton.interactable == false) { //allows the start button to be used startButton.interactable = true; } } }