Many people are confused by the use of the word "regulation", using it when what they mean to refer to is the size of tables used for professional tournaments. Regulation tables come in 3.5 ft by 7 ft, 4 ft by 8 ft, 4.5 ft by 9 ft, 5 ft by 10 ft, and 6 ft by 12 ft (depending upon factors such as available room in the venue, and what game type the table is intended for) with play areas twice as long as they are wide (plus or minus 1/8 in) from the nose of the cushion to the nose of the opposite cushion, i.e., perfect or close to perfect rectangles. The 4.5 ft by 9 ft model is the standard size for tournament play and is "regulation" when the side to side internal width is 50 in and the length is 100 in (plus or minus 1/8 in), when measured cushion nose to cushion nose. In previous generations 10 ft tables were standard for pool, and can still be found as antiques in some pool halls; this size remains the standard for carom games. For home use, 8 ft tables are somewhat common, but infrequently used elsewhere. Snooker tables, the largest at 12 feet when full-sized, have smaller pocket aperatures than pool tables, as do models for Russian pyramid. The 7 ft models, usually coin-operated, are typically found in bars/pubs due to limited space, and are also used for the Korean game of four ball. Coin-operated pool tables use multiple ways to determine the cue ball from the object balls, including light sensors, different ball sizes/weights, or magnetic triggers.
While most tables are rectangles, there are novelty tables which are round, hexagonal and even zig-zag shaped. These variants, however, are all far less popular than the ubiquitous, traditional rectangular tables.