BC and CB are right. A friend kept sending me scripts that got converted to Ariel on my machine. It looked horrible.
We needed to solve the problem because I had to send his script to an agent. Embedding the font solved the problem.
And yes, .pdf is the norm. I rarely get a request for a hard copy these days. Financiers, producers, sales agents, casting directors, directors etc - mostly they all request .pdf.
There are still a few stuffy UK agencies that insist on hard copies but I even managed to convince some of them to accept a .pdf.