Outside bets are placed outside the numbered grid and cover large groups of numbers. They have a higher probability of winning:
Red / Black: A bet on the color of the winning number. Pays 1 to 1.
Even / Odd: A bet on whether the number is even or odd. Pays 1 to 1.
Low / High: A bet on numbers 1-18 or 19-36. Pays 1 to 1.
Dozen: A bet on groups of 12 numbers (1st, 2nd, or 3rd group). Pays 2 to 1.
Column: A bet on one of the three vertical columns. Pays 2 to 1.