Victory! Very simple. Great job on completing a game!

So let's try some math! The expected value of a given non-death roll (since in east Asian cultures 4 is associated with death I presume) is (1+2+3+5+6) / 5 = 3.4. Thus, each successful game requires on average 100 / 3.4 = 29.4 rolls. 

The chances of rolling 29 non-4 die rolls in a row can be calculated like this: not rolling a 4 is a 5/6 chance, and since we have to do that 29 times we have to multiply by itself 29 times, so (5/6)^29 is .00506, which is a .51% chance of success. Taking the inverse by raising it to the -1, we see there's a 1 in 198 chance of rolling 29 non-4s in a row.  (Or more accurately if we use 29.4 we get 213)

But I got a B- on a probability test once, so let's check that math with a program:

function bestGame() 
{     
    var sum = 0;     
    while(sum < 100)     
    {         
        var roll = parseInt(Math.random()*6) + 1;
        if(roll == 4)         
        {             
            return false;         
        }         
        sum += roll;     
    }     
    return true; 
}  
function testGame(trials) 
{     
    var wins = 0;     
    for(var i=0; i<trials; i++)
    {
        wins += bestGame();
    }
    return wins / trials;
}
testGame(100000);

And when run, I got a value of .00483 (though it varies a little each time), or a 1 in 207 chance of winning, and that's pretty close to our ideal value.

Thus, it looks like your chance of winning is actually about 1 in 213, because that's the ideal value.

Interesting idea, though the right key could just be spammed until a 4 appears.

To be honest the idea is clever. It is even funny ! Maybe aesthetic could be improved :)

Em, okay I guess ?