Script to determine the outcome(s) of any number of dice rolls
Use unpacking

        choices = roll_choice.split()
        size = len(choices)
        if size == 3:
            one = int(choices[0])
            two = int(choices[1])
            three = int(choices[2])
            dice_roller(one, two, three)
        else:
            print "Invalid Choice.\n"


Becomes:

dice_roller( * map(int, roll_choice.split()) )


Adding error handling it is:

 try:
     dice_roller( * map(int, roll_choice.split()) )
 except Exception as e:
     print("Invalid choice:" + e)


The * operator just goes from a list to free floating arguments and is called the unpacking operator. You use it to pass a list as argument to a function that takes separate arguments.

Naming in full

You should write the names of your variables in full to make them more understandable at first glance. show may be omitted. For example:


show_di_1 ➡ dice_1
show_di_b ➡ dice_bottom


A dictionary

A dictionary will allow you to avoid the first if elif chain easily. How is left as an exercise for the reader.