CodeAcademy's JavaScript Rock,Paper,Scissors, Rope. This does all the 3, check the user's input, added choice of rope, in case of a tie it asks users or new input.

rock_paper_scissor_rope.js

            var choice = function()
            {
                    var userChoice = prompt("Select rock, paper, scissors,rope");
                    if(userChoice!=="rock" && userChoice!=="paper" && userChoice!=="scissors" && userChoice!=="rope")
                    {
                        alert("You have entered wrong choice, enter rock, paper, scissors or rope");
                        choice();
                    }
                    else{
                    var computerChoice = Math.random();

                    if(computerChoice<=0.25){
                        computerChoice = "rock";
                    }
                    else if(computerChoice<=0.50){
                        computerChoice = "paper";
                    }
                    else if(computerChoice<=0.75){
                        computerChoice = "scissors";
                    }
                    else{
                        computerChoice = "rope";
                    }
                    alert("The Computer's choice is:- "+computerChoice);
                    var answer = compare(userChoice,computerChoice);
                    alert(answer);
                    }
            
            };

            var compare = function(choice1,choice2)
            {
                if(choice1===choice2)
                {
                    alert("It's a tie! You must select another choice!");
                    choice();
                    return compare(userChoice,computerChoice);
                }
                
                else if(choice1==="rock")
                {
                    if(choice2==="scissors")
                    {
                        return("Rock wins! You've won!");
                    }
                    else if(choice2==="paper")
                    {
                        return("Paper wins! You lose!");
                    }
                    else
                    {
                        return("Rope wins! You lose!");
                    }
                }
                else if(choice1==="paper")
                {
                    if(choice2==="rock")
                    {
                        return("paper wins! You've won!");
                    }
                    else if(choice2==="scissors")
                    {
                        return("Scissors wins! You lose!");
                    }
                    else
                    {
                        return("Rope wins! You lose!");
                    }
                }
                else if(choice1==="scissors")
                {
                    if(choice2==="paper")
                    {
                        return("Scissors wins! You've won!");
                    }
                    else if(choice2==="rock")
                    {
                        return("Rock wins! You lose!");
                    }
                    else
                    {
                        return("Rope wins! You lose!");
                    }
                }
                else if(choice1==="rope")
                {
                    if(choice2==="paper")
                    {
                        return("Rope wins! You've won!");
                    }
                    else if(choice2==="rock")
                    {
                        return("Rope wins! You win!");
                    }
                    else
                    {
                        return("Rope wins! You win!");
                    }
                }
            };
            choice();