A wheel with real odds
On most wheels every item is the same size, so everything is equally likely. Here each prize says how much of the wheel it is worth: the grand prize is a sliver, “try again” is a tenth of the circle, and what you see is exactly what the odds are:
How to set the odds
Write a weight at the end of a line and the segment grows to match. A line without one is worth one:
Grand prize|x1andTry again|x10– the grand prize comes up once in eleven spins.Coffee|#795548|x6– a colour and a weight, in that order.- Weights do not have to add up to anything. The wheel divides the circle by their total.
- Two prizes with the same weight are equally likely, as on any wheel.
The wheel as published is 1 : 4 : 6 : 9 : 10, so the grand prize comes up about three times in a hundred spins.
Who uses it
- Shops and markets: a spin for every customer, with a real prize on the wheel.
- Streamers and giveaways, where the odds are announced.
- Classrooms: mostly stickers, and once in a while no homework.
- Parties and fundraisers – a tombola where the big prize stays rare.
One prize per person
Under Options, Take the winner off the wheel removes a prize once it is won, for a wheel with one of each. Leave it off for a wheel that keeps its odds all day:
Past winners is the record of who won what:
Fair, and visibly so
Where the wheel stops is decided by your browser at the moment you press the button, and the segments are drawn to the weights you set – so the picture on screen is the odds. Anybody watching can see that the grand prize is a sliver.