Weighted Spin Wheels Explained
A weighted wheel gives different entries different selection chances. SpinAndDecide represents each positive integer weight as a number of tickets, chooses one ticket uniformly and maps that ticket back to an entry. The segment size follows the same proportions. This guide explains how to write weighted entries, calculate their odds and avoid confusing unequal selection with a fair one-person-one-chance draw. Weights are useful when the distribution is intentional and disclosed; they do not infer merit, preferences or sporting probability.
By SpinAndDecide · Updated November 4, 2026
Start with the question weights are meant to answer
Before entering numbers, write down why the choices should differ in likelihood. An activity designer may want a common prompt to appear more often than a rare bonus. That is a different goal from choosing one participant equally from a roster. If every person should have one chance, leave weighting off and enter each person once. A larger segment is a larger chance, not merely a decorative emphasis or a visual priority marker.
Use the supported entry format
Turn on Weighted entries and write every line as a label, a vertical bar and an integer from 1 to 1000. For example, Common prompt | 3 and Bonus prompt | 1 create four total tickets. Every nonblank line needs its own valid weight while weighted mode is enabled. Fractions, negative values and zero are not supported. To exclude an option, delete its line rather than giving it a zero weight that the parser will reject.
Calculate probabilities from the total
Add all weights first. An entry’s probability is its own weight divided by that total. With weights three and one, the first entry has three quarters of the chance and the second has one quarter. Weight three does not mean three percent unless the total happens to be one hundred. The displayed odds note reports the total ticket count so you can compare the editor with your arithmetic. Review the whole list before drawing, especially after deleting an entry.
Recognize equivalent distributions
Multiplying every weight by the same positive factor preserves the proportions. Weights two and four produce the same one-third versus two-thirds distribution as weights one and two. Smaller equivalent integers are easier to inspect and share. Reordering entries does not change their weight-based probabilities. Duplicate labels, however, are separate entries; their chances add at the label level. If the same visible name appears twice, explain whether those are distinct eligible tickets or an accidental duplicate.
Understand what removal changes
Remove winner deletes the selected line after the reveal, including that line’s entire weight. It does not subtract one ticket from the weight. A three-ticket entry chosen once therefore leaves the active pool entirely. If you want ticket-by-ticket depletion, use separate uniquely identified ticket lines and manage person-level rules yourself. Removing a winning line changes the total and therefore the next draw’s odds. Decide whether your activity calls for independent repeats or this changing pool before beginning.
Keep weights away from dice and team allocation
Ordinary dice need equal independent faces, and the dice mode rejects weights and winner removal. Team allocation also rejects weighted participants because every roster entry must occupy exactly one position in the shuffled allocation. Do not approximate a skill-balanced team system by giving stronger players a larger random weight. That changes selection chances rather than ensuring balanced teams. Where skill or support needs matter, choose an appropriate grouping process and explain any organizer adjustments openly.
Explain the random method without overstating it
The browser obtains cryptographic random values and rejection sampling maps them to the eligible ticket interval without a modulo remainder bias. Once a ticket is selected, the animation reveals the matching entry. That technical mapping does not verify the eligibility of your list or make an undisclosed distribution fair to participants. A browser operator can also edit local entries and code. Describe the algorithm and the organizer’s process as separate parts of the activity.
Review an example before using real labels
Try three sample entries with weights one, two and three. The total is six, giving probabilities one sixth, two sixths and three sixths. A few test spins will not necessarily match those proportions closely, and an unlikely outcome can repeat. Use the arithmetic and visible segment proportions to inspect the setup rather than treating a short run as proof. When satisfied, replace the samples with the intended labels and disclose the final distribution where participants need to understand it.
Frequently asked questions
Does weight 5 mean five percent?
Only if all entry weights add to one hundred. The general probability is five divided by the total weight.
Can I use decimal weights?
No. Use integers from one to one thousand. Equivalent whole-number ratios can express many fractional proportions.
Does removal subtract one ticket?
No. It deletes the selected entry line with its complete weight. Separate ticket lines are needed for ticket-level depletion.
Are weighted draws unfair?
They are intentionally unequal by entry. Whether they suit an activity depends on the disclosed rules and eligibility process.