Dozen bet. A bet that the number will be in the chosen dozen: first (1-12, Premire douzaine or P12), second (13-24, Moyenne douzaine or M12), or third (25-36, Dernire douzaine or D12). Column bet.
First dozen / Premiere douzaine: numbers 1 - 12 (On the French-style mat, the square marked 12P) Middle dozen / Moyenne douzaine: numbers 13 - 24 (On the French-style mat, the square marked 12M)Last dozen / Dernier douzaine: numbers 25 - 36 (On the French-style mat, the square marked 12D)