When writing a script for a dramatic scene, are the characters listed horizontally or vertically?

Answer 1

Usually vertically.

Answer 2

The thing is that my teacher said that the characters should come out in the order the come in the play, so it seems unclear about how to follow these instructions if I show the characters vertically.

Answer 3

If I have three characters in each column, then how would I follow those instructions?

Answer 4

I have no idea why you're to put these in three columns! Baffles me!!

This is what a cast (dramatis personae) looks like in standard form:

http://www.bartleby.com/70/4201.html