<Tr> <Th> Playing time </Th> <Td> less than 15 minutes </Td> </Tr> <Tr> <Th> Skill (s) required </Th> <Td> Tactics, strategy </Td> </Tr> <P> Dominoes is a family of tile - based games played with rectangular "domino" tiles . Each domino is a rectangular tile with a line dividing its face into two square ends . Each end is marked with a number of spots (also called pips, nips, or dobs) or is blank . The backs of the dominoes in a set are indistinguishable, either blank or having some common design . The domino gaming pieces (colloquially nicknamed bones, cards, tiles, tickets, stones, chips, or spinners) make up a domino set, sometimes called a deck or pack . The traditional Sino - European domino set consists of 28 dominoes, featuring all combinations of spot counts between zero and six . A domino set is a generic gaming device, similar to playing cards or dice, in that a variety of games can be played with a set . </P> <P> The earliest mention of dominoes is from Song dynasty China found in the text Former Events in Wulin by Zhou Mi (1232--1298). Modern dominoes first appeared in Italy during the 18th century, but how Chinese dominoes developed into the modern game is unknown . Italian missionaries in China may have brought the game to Europe . </P>

What are the dots on a domino called