In Mega Millions drawings, you can pay an extra dollar for the "Megaplier" feature. The Megaplier multiplies the payout by a randomly selected number from 2 to 4, for all prizes other than the jackpot.
The Megaplier number is selected from a hopper with 21 balls in it, but they only have the numbers 2 through 4 on them. The numbers are distributed unevenly, with 12 fours, 7 threes, and 2 twos in the hopper. Since September 2010, anyone who pays for the Megaplier option who gets 5 numbers without the Mega Ball gets $1 million, regardless of what Megaplier number is selected. In other words, a $1 million second prize is guaranteed to anyone who paid the extra $1 for the Megaplier feature.
The Megaplier option is available in 43 of 44 states offering Mega Millions, with California being the only state that doesn't offer it. The multiplier number 4 is selected 57.1% of the time, while the number 3 is selected 33.3% of the time and the 2 is selected only 9.5% of the time.