A roulette is a curve traced by a fixed point on a closed convex curve as that curve rolls without slipping along a second curve.


Roulette is a also a gambling game in which the players bet on which slot of a rotating disk a small ball will come to rest in. On August 18, 1913, on an unbiased roulette wheel at Monte Carlo, evens came up 26 times in a row. The probability of this occurring is 1 in 136,823,184.