roll3.py

import random
from collections import Counter

def roll(die_size, die_count):
    return (random.randint(1, die_size) for _ in range(die_count))

def is_good_roll(rolls, threshold):
    c = Counter(rolls)

    return any(x >= threshold for x in c.values())

if __name__ == '__main__':
    trials = 10000000
    good_rolls = 0

    for _ in range(trials):
        if is_good_roll(roll(12, 12), 3):
            good_rolls += 1

    print(good_rolls, good_rolls / trials)