Except when clearly contradicted by these additional rules, the General Rules of Pocket Billiards apply.
These are our interpretation of the BCA rules of the game (from their 1992, and 2005 rule books). For a more concise description see Bob Jewett's answer on the rules at Rules clarification for Bowlliards, Equal Offense on AzBilliards Forums. We opted to ignore fouls penalties. We also decided to go with coming out of the kitchen for picking up the spare whether there was a foul on the previous shot or not (it was quite a discussion).
Bowlliards is a game that applies the scoring concepts of bowling to pocket billiards. It is one of the few games that can be quite interesting as a solitary exercise since, like bowling, there is a perfect game score to strive toward, and a player can measure his improvement quite easily over the course of time playing Bowlliards.
Any number of people (for reasonable completion times figure four to six individuals per table).
In solitary play, to get a perfect score of 300 points in 10 frames. In competition, to score a higher point total in 10 frames than your opponent(s).
Standard rack position (front apex ball on foot spot), using balls 1-10 (a four row rack).
Each legally pocketed ball is scored as one point, regardless of ball number. The points scored as per the "Rules of Play" below are treated exactly as is the pinfall in bowling.
At the start of a player's frame, he has a free break (no special balls-to-cushion or other requirements once break stroke play commences, and a jumped or scratched cue ball is without penalty). Any balls pocketed on the break are spotted, and the player then follows his break by beginning scoring play with object balls in position and cue ball in hand behind the head string. The opening break takes place at the start of every frame.
A legally pocketed ball entitles the shooter to continue at the table until he fails to pocket a called ball on a shot, or until he has scored the maximum total per inning possible (10). Player may shoot any ball he chooses, but before he shoots, must designate a single ball that he will pocket and the pocket into which the ball will score; he need not indicate kisses, caroms, combinations or cushions (none of which are illegal).
Player has two chances to pocket the 10 possible balls of each frame. If player legally pockets ten consecutive balls on his first chance of a frame, that frame is completed and player scores the frame exactly as a strike in bowling. If player fails to pocket 10 consecutive balls on his first chance, he takes his second chance immediately. If he succeeds in legally pocketing the remaining balls on the table, the frame is completed and player scores exactly as a spare in bowling. If player fails to legally pocket all ten balls in two chances, the frame is then completed and is scored as an open frame in bowling. All succeeding frames are likewise scored just as in bowling; a "strike" in the tenth frame earns two extra innings, a "spare" one extra inning.
If players tie for high game total in competition, additional innings are played alternately by the tied players, with the first player posting a superior score to that of his opponent(s) being the winner ("sudden death").
On the (free) break, pocketed balls are spotted prior to the player beginning his scoring play (first chance of frame). During scoring play, illegally pocketed balls are spotted.
All spotted; no penalty.
Only applies if occurring as player's first foul of a frame: player has cue ball in hand behind the head string to begin his second chance of the frame.
No points are deducted (note that balls dropped on a foul stroke do not count and must be spotted). If the foul ends player's first chance of a frame, he has cue ball in hand behind the head string to begin his second chance of the frame. If the foul end's his second change (the one to pick up a spare) then his frame is finished.