For full details see The Joy of Bocce Weekly - Volume II, Issue #24 (Click on the Back Issues button to view the Archives).
The US Bocce Championships held on June 8-15, 2003 at the Highwood Bocce Courts, Highwood, IL included the International volo style play discussed here.
The Highwood courts have a fast-playing synthetic surface that might have been damaged by volo shooting (volo entails tossing brass bocce balls into the air in an attempt to displace an opponent's ball or the pallino). If you want to hit a ball, you must first call your shot, then strike it with a volo attempt - no raffa, or fast rolling hitting is allowed.
Each end of the court is marked with three white lines. From the back wall these measured .5 meter, 2.5 meters, and 7.5 meters. Any ball that passes the 1/2 meter mark is "dead" no matter how it gets there. To begin a frame, the pallino must come to rest between the 2.5 and the 7.5 meter lines. Also, the 7.5 meter mark is the foul line for both pointing and hitting.
Some Volo rules to consider.
When pointing, your foot must be completely behind the foul line (as opposed to the other international game - Punto, Raffa, Volo - where your foot may be on the line).
The side walls are dead (court surface is canted at both sides to minimize chances of this happening).
If the pallino touches the boards the frame is over.
Every hit must be a Volo, whereas in (Punto, Raffa, Volo) a fast-rolling hit can be employed.
When you call a shot, the referee scribes a 50 cm arc in front of the target ball. Your ball must land within this arc to be a valid hit, otherwise the Rule of Advantage applies.
Rule of Advantage, as in Punto, Raffa, Volo play, means that the offended team can take the result of the play or "burn" the illegally tossed ball and replace all displaced balls to their previous positions.
If a rolled ball results in the displacement of any object a distance equal to or greater than the length of the referee's stick (50 cm), the opposing team may "burn" the ball and return the moved balls to their previous positions.
Note: the positions of all balls are marked.
After rolling or shooting you must go to the other end so as not to interfere with the next player's roll.
More Volo points...
The brass volo balls are a tad smaller than the traditional 107 mm plastic balls and some contain a special rubber material in the core that absorbs bounce. So, you can hit just in front of the target and, instead of bouncing over, your shot is likely to strike its intended target.
When pointing, you don't have to worry so much about displacing balls 50 cm, as their composition is such that they don't roll too far after being struck, even on fast surfaces.
Sometimes it is difficult to distinguish one team's bocce balls from another's (colors are similar), but distinctive lines etched on the balls' surface make for easy identification on closer inspection.
Games are long - these matches went to a set number of points (13 or 15) or a time limit (1 1/4 hours to 1 1/2 hours) whichever came first.
Singles play - 4 balls each = 8 balls in play
Doubles = 3 balls each = 12 balls in play
Triples = 2 balls each = 12 balls in play