Dominoes, DOM uh nohz, are small, flat, oblong tiles used to play a variety of games. Dominoes were probably invented in China, then introduced in Europe in the 1700's. Most sets of dominoes are made of bone, ivory, plastic, or wood. A regular set consists of 28 dominoes. A line divides each domino into two sections. Each section of 21 of the dominoes is marked with from one to six dots. Both sections of another domino are blank, and the six remaining dominoes have one blank section and one section with dots. Every possible combination of dots appears in a domino set, and no two dominoes are alike.