The claim: Anyone can win £50 million by correctly predicting the result of all 51 games in the Euro 2016 football championships. Vote Leave says this figure represents the amount of money the UK sends to the EU every day.
Reality Check verdict: Unlikely anyone could win this prize. The odds of winning are only slightly better than the odds of guessing the mobile phone numbers of the next two strangers you see in the street. The UK does not send £50 million a day to the EU.
But, as the Reality Check team have been finding out, the chances of winning are staggeringly small.
There are a total of 36 games in the group stage of the tournament and 15 knockout matches.
The odds of correctly forecasting all 51 games randomly are a sextillion to one.
Now, your in-depth knowledge of European football may tip the odds more in your favour, but remember you also have to guess which teams will qualify from the group stages.
The finals feature 24 teams for the first time and with 16 of them qualifying for the first knockout round, the results are harder to predict.
Even if you had a 70% chance of getting each one right, the odds are probably about one in 80,000,000 - quite a bit worse than your chances of winning the lottery (45,000,000 to one since you ask).
Vote Leave recognise that the odds are slim but campaign director Dominic Cummings defended the contest, saying: "We want everyone to have the chance to win the sort of money most people can only dream of, unless they are a banker or a Euro MP."
For the record, MEPs earn 8,213 euros (about £6,250) per month.
To qualify for the prize, participants have to enter their phone number, together with their email and home addresses, with a Vote Leave source admitting it would allow them to gather the contact details of thousands of potential voters.
Will Straw, executive director of Britain Stronger In Europe, described the competition as a "con".
But Vote Leave's privacy policy allows anyone to "opt out" from receiving campaign information "at any time".
Odds aside, Vote Leave have based their competition prize figure on the assertion that the UK sends £50m a day - or £350m a week to the EU. They've been sharply reprimanded for this by Sir Andrew Dilnot, the chairman of the UK Statistics Authority for using it. He described it as "misleading" and said it "undermines trust in official statistics".
We've looked into this claim before and concluded that once you allow for the rebate and money that comes back to the UK for things like farming subsidies, the UK sends roughly £23 million a day to the EU.
This would be a very tidy lump sum but not nearly as generous as the amount that Vote Leave is offering.
Read more: The facts behind claims in the EU debate
Vote Leave has promised a £50m prize for the person who correctly predicts who they think will win each game of the 2016 European Football Championships this summer.