The dice do not always land on the numbers but the probabilities change, giving cheaters a larger mathematical edge over the house in the long run. Then the cheating players wager on those same numbers and wins more money.
Basically, the main idea is that the dice get altered in some way so that when they are thrown, they land on specific numbers more often than others. Using fixed dice is one of the oldest methods of cheating at dice games and there are a number of ways that players can manipulate the dice. There are a number of ways to cheat at the game of craps.
