Dice deceptions are as old as dice games themselves. Apparently people were always tempted to gain an advantage, although not necessarily in a fair way. Dice relicts were discovered all over the world. Dice motifs were also found on paintings coming from Ancient Egypt, that is more than 3000 years BC.
Any dice is hardly perfect. However current technologies are so accurate that the differences are immeasurable from a human point of view. The ideal dice is quite symmetrical and balanced. This suggests the direction that unfair thoughts may take. The dice deceptions are committed by those who adjust the dice deliberately in order to raise the probability of rolling a specific value.
The dice has a tendency to fall on the widest or the weighted side. The adjusted dice may be slightly grinded on the edge or weighted in a well-hidden way. There have been cases when transparent dice were weighted under a dot. These two are the most frequent “mechanical” dice deceptions. Casinos prevent them by using their own dice exclusively; if they fall off the table they are replaced with new dice immediately.
The other dice deceptions belong to the “skill” category. Some players are able to roll a specific value or to raise its probability to come up. This problem has a solution as well. If you play Craps then you know that it is necessary to roll a dice in a way that it bounces off the cushion of the table. That eliminates the majority of tricks or controlled rolls.
Generally there is a higher risk of fraud if you play in pub conditions (rather than in a casino) and when you do not the players or the origin of dice. Sometimes it may be innocent as the dice can be corrupted right from the production. In any event you should sharpen your attention when some values come up more often than they should, based on the law of probability.