25% Looks
25% Who you know
25% What you know (talent, experience, et al)
25% Passion
0% Luck (there is no such thing in show business. It's all about YOU and THEM).
And when I say "Looks" I don't mean good-looking. I don't care if you're handsome, ugly, have a great build, fat, or disfigured - you will be judged by how you look and if the look is good for the part.
"Looks" is made up of facial features, body type, gender, height, weight, physique, hair, etc. Even clothing. Voice sound, too (not how good you can sing, but the sound).
"Who You Know" is made up of the people that trained you, the people that made you who you are today, agents, contacts, etc.
"What You Know" is made up of your talent, your knowledge, your experience, how well you can sing & dance, etc.
"Passion" is your desire to perform, desire to learn, desire to train, desire to face rejection, desire to experience, desire to observe, desire to try try and try again, desire to never give up. The desire to face any challenge and try to achieve your goal, and accepting the consequences with a smile.
"The Spectacle has, indeed, an emotional attraction of its own, but, of all the parts, it is the least artistic, and connected least with the art of poetry. For the power of Tragedy, we may be sure, is felt even apart from representation and actors. Besides, the production of spectacular effects depends more on the art of the stage machinist than on that of the poet."
--Aristotle