GAMES PLAYED ON CAROM BILLIARD TABLE...

There are 3 major subdivisions of games within cue sports:

• CAROM BILLIARDS, referring to games played on tables without pockets, typically 10 feet in length, including balkline and straight rail, cushion caroms, three-cushion billiards, artistic billiards and four-ball.
• POOL, covering numerous pocket billiards games generally played on six-pocket tables of 7-, 8-, or 9-foot length, including among others eight-ball (the world's most widely played cue sport), nine-ball (the dominant professional game), ten-ball, straight pool(the formerly dominant pro game), one-pocket, and bank pool; and
• SNOOKER and ENGLISH BILLIARDS, games played on a billiards table with six pockets called a snooker table (which has dimensions just under 12 ft by 6 ft), that are classified entirely separately from pool based on a separate historical development, as well as a separate culture and terminology that characterize their play.

Now we will discuss only GAMES THAT ARE PLAYED ON CAROM BILLIARDS TABLE...

Balkline (sometimes spelled balk line or balk-line) is the overarching title of a large array of carom billiardes games generally played with two cue balls and a third, red object ball, on a cloth-covered, 5 foot × 10 foot, pocketless table that is divided by balklines on the cloth into marked regions called balk spaces. Such balk spaces define areas of the table surface in which a player may only score up to a threshold number of points while the object balls are within that region.

The balkline games developed to make the precursor game, straight rail, more difficult to play and less tedious for spectators to view in light of extraordinary skill developments which allowed top players to score a seemingly endless series of points with the balls barely moving in a confined area of the table playing area. Straight rail, unlike the balkline games, had no balk space restrictions, although one was later added. The object of the game is simple: one point, called a "count", is scored each time a player's cue ball makes contact with both object balls (the second cue ball and the third ball) on a single stroke. A win is achieved by reaching an agreed upon number of counts.

Carom billiards players of the modern era may find it surprising that balkline ever became necessary given the considerable difficulty of straight rail. Nevertheless, according to Mike Shamos, curator of the U.S. Billiard Archive, "the skill of dedicated players [of straight rail] was so great that they could essentially score at will." The story of straight rail and of the balkline games are thoroughly intertwined and encompass a long and rich history, characterized by an astounding series of back and forth developments, akin to a billiards evolutionary arms race, where new rules would be implemented to make the game more difficult and to decrease high runs to keep spectators interested, countered by new shot inventions and skills interdicting each new rule.

Three-cushion billiards (sometimes called three-cushion carom, three-cushion, three-cushions, three-rail, rails and the angle game, and often spelled with the numeral "3" instead of "three") is a popular form of carom billiards.

The object of the game is to carom the cue ball off both object balls and contact the rail cushions at least three times before the last object ball. A point is scored for each successful carom. In most shots the cue ball hits the object balls one time each, although hitting them any number of times is allowed as long as both are hit. The contacts between the cue ball and the cushions may happen before and/or after hitting the first object ball. The cue ball does not have to contact three different cushions as long as they have been in contact at least three times in total. Each player has his own cue ball. In modern three-cushion, the neutral ball is red, and the cue balls are white and yellow. The introduction of the yellow ball (instead of two white balls) has not changed any rules, each player has always used a cue ball of his/her own, with small markings on the white balls in order to discriminate them from each other. The yellow ball makes it easier for spectators to follow the game.