Odds for a 1–12 draw
There are 12 possible results, so each number has a 1 in 12 chance (8.33%) of being picked on any single draw. Each draw is independent: getting 12 once doesn't make it more or less likely next time.
Need something more visual? Try the spinning wheel or the dice roller.
Pick several numbers at once
Change "How many numbers" to generate a list. Untick "allow duplicates" to get unique numbers, up to all 12 in a random order.