Teaching myself Python. This is a simple random dice roller. Input a number of dice to roll (like 3d6) and a modifier if you have one (like bonus damage!) and this snip of code will calculate the total using randint as a randomizer.

1d20 Roller

from random import randint

while True:
    string = str(raw_input("Dice: "))   #how about "3d6", for example
    split = string.split("d")           #create a list containing 3 and 6
    modifier = None
    while modifier is None:
        modifier = int(raw_input("Modifier: "))
        if modifier is "":
            modifier = 0
    num_dice, hedrons, rolls, total, die = int(split[0]), int(split[1]), 0, 0, 0
    while rolls < num_dice:             #we will roll the die 3 times
        die = randint(1, hedrons)       #roll a d6 and discover result
        print "1d%d rolled: %d." % (hedrons, die)
        rolls = rolls + 1               #roll again if necessary (up to 3 times)
        total = total + die             #keep a tally of all die rolls
    max_damage = num_dice * hedrons + modifier
    print "Modifier is %d." % modifier
    print "Total roll: %d. (max: %d)" % ((total + modifier), max_damage)