In American roulette, the table has tiles labeled 1st, 2nd and 3rd. The corresponding drawers on the French table are arranged in two areas and labeled 12P , or Premier Douzaine (numbers 1 through). 12), 12M , or Moyenne Douzaine (numbers 13 to 24) and 12D , or Dernire Douzaine (nos. 25 to 36).
Kind of Play
Odds multiplied by the Stake
On the first 12 numbers. i.e. 12P or P12 (1-12)
2 to 1
On the middle 12 numbers, i.e. 12M or M12 (13-24)
2 to 1
On the last 12 numbers, i.e. 12D or D12 (25-36)
2 to 1
On a vertical column of 12 numbers (1-34, 2-35, 3-36)
2 to 1