Random Number Between 1 and 3
The box above gives 1, 2 or 3, each with the same chance. It draws one when the page loads and another whenever you press the button, with no link between the two.
1 to 3 1
3 possible values, each equally likely. Tick nothing and repeats can happen; that is what random means.
The odds
Three outcomes, 33.33 per cent each, or one chance in three. Both ends are included, so 1 and 3 are as likely as 2.
Repeats are normal at this size
With only three values, the next draw matches this one a third of the time. Draw three times and the chance of seeing all three different numbers is just 22.2 per cent, so more than three times in four a set of three draws repeats something. Seeing the same number twice running is not the tool sticking. On average it takes 5.5 draws before all three values have appeared at least once.
Without a computer
Roll an ordinary die and halve it: 1 or 2 means one, 3 or 4 means two, 5 or 6 means three. Each pair covers two of the six faces, so each result lands on exactly one in three. That is a clean split, which is more than most die-to-range tricks manage. Rock paper scissors is not a substitute, because people do not throw the three shapes evenly.
What it is for
Three-way choices with nothing to separate them: which of three places to eat, which of three jobs to start with, which of three people goes first. Nearby ranges are 1 to 4, 1 to 5 and 1 to 6, and any other range is on the random number generator. If the three options are names rather than numbers, paste them into the picker.