It looked fine from my board but it kept showing that message. After I pasted it on question board, I could see what is wrong with indentation. so I went back and forth, copy and paste to correct indentation.
Now it shows different messages saying "command not found".
I thought roll_dice(6) as command. Did I miss colon or something,,,?
'''This is a computer dice game'''
from random import randint
from time import sleep
user_guess = int(raw_input("Guess a number: "))
first_roll = randint(1, number_of_sides)
second_roll = randint(1, number_of_sides)
max_val = number_of_sides * 2
print "The maximum possivle value is:" + str(max_val)
user_guess = get_user_guess
if user_guess > max_val:
print "No guessing higher than the maximum value!"
print "The first value is: %d" % (first_roll)
print "The second value is: %d" % (second_roll)
total_roll = first_roll + second_roll
if user_guess > total_roll:
print "There you go!"
print "Try again"