The fourth-largest lottery prize in US history will be on the line as numbers are drawn for the Mega Millions game's $US654 million (NZ$996 million) jackpot.
The grand prize for tomorrow's (NZT) draw has grown so enormous because no one has won the jackpot since July 24.
Although the jackpot is massive, the odds of matching all six numbers and becoming instantly wealthy are remarkably small at one in 302.5 million.
The estimated $US654 million jackpot refers to the annuity option, paid out over 29 years. The cash option, which is favoured by nearly all winners, is $372 million (NZ$566).
Mega Millions is played in 44 states, Washington, D.C., and the U.S. Virgin Islands.