The Rules of Bowls .
There are many varieties of the game of bowls. For the purposes of this document, three of the most popular variations are given, Lawn Bowls, Crown Green Bowls and Table Bowls. In all, the basic rules of the game are exactly the same - it is only the equipment and the playing area that differ. Accordingly, the descriptions of each game are given separately but the common rules of play are given only once. As in all such games, specific rule variations abound according to the area and the club or pub. These rules are comprehensive instructions for friendly play. They are not a complete set of standard regulations encompassing all situations that might be encountered. If in doubt, players should always abide by locally-played or house rules. Please note that 1 metre = 100 cm = 3.28 feet. 3 feet = 1 yard.
Bowls - Basic Play
The Equipment
Each person has a set of uniquely marked bowls called "woods" which are slightly eccentric balls - each bowl is a tad less than spherical on one side. The resulting weight differential is called the "bias" and woods are rolled with the bias on the left or right side so that the bowl adopts a curved path towards the target. In the past woods were normally made from lignum vitae but these days hard rubber or a compound material is often used. The target is a smaller ball, usually white, called a "jack".
The Play
A coin is tossed to decide which player will start the first "end" or "leg". After that, the player who won the previous end bowls the first wood of the next one.
To start, players take turns to bowl the jack until one bowls it to a position that is in accordance with the rules. The player who is to bowl the first wood of the end is the player who has the first chance to bowl the jack. Under most circumstances, the first try is all that is needed.
Once the first wood has been bowled, the other players then take turns to roll their bowls towards the jack. Woods are not always played with the aim of being closest to the jack - they are often played to knock opposing woods out of contention or to move the jack or other woods of the same team into a more advantageous position.
The winner of the leg scores one point for each wood that is closer to the jack than the opposing team's closest wood. The player or team that first reaches 21 points or some other amount agreed up front, wins.
The Equipment
A standard bowling green is a flat square lawn between 33 and 44 yards long. Delimiting the edge of the lawn is a ditch. The surface is divided into strips or "rinks" 19 to 21 feet apart so that multiple games occur across the whole lawn, one in each rink.
The unbiased jack is 2 1/2 inches in diameter while the woods are 4 3/4 - 5 1/8 inches in diameter and weigh 2lb 12oz - 3lb 8oz.

From Philipp and Marian