How the wheel picks
Every slot is the same size, so each option has exactly a 1-in-n chance — 1 in 2 for yes or no, 1 in 12 with a full wheel. The slot is fixed by a random code drawn the moment you press Spin; the spinning is just for show.
The code sits at the end of the link, so everyone you send it to watches the same spin land on the same slot. Handy for who pays, which movie, what to cook or a party penalty.
How does Spin the Wheel pick an answer?
Pressing Spin makes your browser draw a random 8-character code and add it to the end of the link, after the options. The code, the tool name and the list of options are hashed together (FNV-1a) to seed a mulberry32 random number generator. Its first number picks the slot: multiply by the number of options and round down. The next two only shape the animation: 5 to 7 full turns, and a stopping point 20–80% of the way into the slot, so the pointer never rests on a line.
Nothing else feeds the result: no weighting, no history, no account. The options live only in the link, joined by tildes, up to 12 of them at 20 characters each, so the whole link stays under 1,500 characters. Changing one option, or just its place in the list, gives a different spin for the same code. The Korean lunch preset fills in 8 of our 38 lunch dishes at random each time you tap it; after that they are ordinary options.
Keep in mind it's for everyday decisions, not prize draws that come with legal rules. Anyone you send the link to can read every option. Spinning again creates a new code and a new link, so agree beforehand that the first spin is the one that counts.