Some of the more prevalent today and historically are (chronologically by apparent date of development): straight rail, one-cushion, balkline, three-cushion and artistic billiards.

The Union Mondiale de Billard (UMB) is the highest international governing body of competitive carom billiards.

But this may simply be folk etymology, as the fruit bears no resemblance to a billiard ball, and there is no direct evidence for such a derivation.

[4] In modern French, the word carambolage means 'successive collision', currently used mainly in reference to carom or cannon shots in billiards, and to multiple-vehicle car crashes.

Queen Victoria (1819–1901) had a billiard table that was heated using zinc tubes, although the aim at that time was chiefly to keep the then-used ivory balls from warping.

The quest for an alternative to ivory was primarily driven by economic considerations and concerns for the safety of elephant hunters, rather than environmental or animal-welfare issues.

The impetus for this search was, in part, the announcement by New York billiard table manufacturer Brunswick-Balke-Collender offering a $10,000 prize for the development of a substitute material.

However, while celluloid was a viable substitute, it proved to be volatile and highly flammable, with instances of explosions occurring during its manufacturing process.

Typical carom cues are 140–140 cm (54–56 in) in length and 470–520 g (16.5–18.5 oz) in weight – lighter for straight rail, heavier for three-cushion – with a tip 11–12 mm (0.43–0.47 in) in diameter.

[11] These dimensions make the cue significantly stiffer, which aids in handling the larger and heavier balls used in carom billiards.

In some carom games, deflection plays a large role because many shots require extremes of side-spin, coupled with great speed; this is a combination typically minimized as much as possible, by contrast, in pool.

[1] Straight rail is still popular in Europe, where it is considered a fine practice game for both balkline and three-cushion billiards.

[13] Ultimately, however, despite its divergence from straight rail, the champion's game simply expanded the dimensions of the balk space defined under the existing crotch prohibition which was not sufficient to stop nursing.

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.

[1] By contrast, in 71.2 balkline, of French invention, lines are drawn 71 centimetres (28 inches) distant from each rail, also with a two-count restriction for balk spaces.

[19] The first three-cushion billiards tournament took place 14–31 January 1878, in St. Louis, with McCreery a participant and Leon Magnus the winner.

[20] The game was infrequently played, with many top carom players of the era voicing their dislike of it, until the 1907 introduction of the Lambert Trophy.