Check out the Princess site - do a search on cigar smoking and there are listing for where cigar smoking is allowed - there are places it's not allowed athough cigaretta smoking is. One side of the ship is designated as smoking in the pool areas and outside. Most of their ships actually have a cigar and pipe 'room' - very nicely done down in the public areas.
From the site:
Smoking is not allowed in the dining rooms, or any other food service area, or in the show lounges and theaters. Smoking is permitted in staterooms, stateroom balconies, and designated areas. As a courtesy to your fellow passengers, please refrain from smoking pipes and cigars in all public rooms.
Brilliance of the Seas
smoking is allowed on balconies and so are cigars. There are only a few lines that have put any limits to what guests do in their own cabins. The public areas are different. YOu won't get much smoke. Most lounges have smoking and non smoking areas, the casino has a couple non smoking nights and the dining rooms and show rooms are non smoking as well as one side of the ship.