1. Literally, dice that have each been weighted to one side so as to increase the odds of their landing on the opposite number. When they found out we'd been using loaded dice, they threw us out of the club and told us to never come back.

2. By extension, a means of gaining an advantage through the exploitation or manipulation of rules or regulations. At the height of the economic boom, investment bankers were using sub-prime mortgages with falsified credit ratings as loaded dice to make as much money as possible.