Like cause and effect could be none, work little, or be as great as it was intended. The point to what I'm saying I have made my own as well as others, if you update it to be more modern it should have little to do with it. Its how much you believe in it working. Example I was sitting at a blackjack table, with the money I had in front of me I could maybe go 3 hands. Being that I don't do spells that much I couldn't remember any off hand, so I started chanting to myself something that sounded good and believed in what I was saying with each hand. Now some could argue that it was all luck or as I would like to think it was a riddle and my focus. Again it doesn't always work too.
I hope that helps, for me its my strong belief in myself over everything else