The popular game of craps actually developed from an Old West pastime known as hazard. A favourite throughout the 17th and 18th centuries, hazard has the more complicated rules of the two, but all you need to play is a pair of dice. Any number of players can play at a time. Just one of them, known as the “caster”, can handle the dice at a given time. Before rolling, the caster has to call out a number between five and nine; this number is known as the “main”. The caster then rolls the dice. If they land on a two or three, the caster automatically loses. If they land on the main, the caster wins. A winning roll in hazard is called a “nick” or “throw in”, while a losing roll is called a “throw out”.
This is where the rules get a little tricky. If you roll an 11 or 12, there can be several different outcomes. If you chose five or nine as the main, you throw out. If you went for six or eight and roll an 11, it’s also a throw out, but if you roll a 12, it’s a nick.
But wait, there’s more: If you roll an 11 on a main of seven, you throw in, but if you roll a 12, you throw out. If you roll neither a nick nor a throw out, it’s called a chance and you roll again. If you then roll your main, you lose, but if you roll what the chance was, you win. If you don’t roll either of these, you keep rolling until you do. You get to keep “casting” until you lose three times in a row; then the person to your left becomes the new caster. Picking the number seven as your main gives you the highest probability of winning (0.492) and the lowest disadvantage of losing (1.41%). The worst numbers to pick as your main are six and eight (0.488 winning probability, 2.34% disadvantage).