The National Lottery will launch a format shake-up with new Lotto rules introduced with tonight's draw.

The National Lottery's draw, which takes place every Wednesday and Saturday night at 8pm, will now have a two-round format. From tonight's draw there will be two sets of six main numbers and a bonus ball drawn using two separate machines.

This means the new format will automatically enter players into two separate rounds in every draw. Players, however, do not have to make any changes to the way they play their games, and will only have to continue to pick six numbers from 1 to 59. Players will still receive prizes by matching two or more main numbers in a single round.

There will also continue to be two ways to become a millionaire: by matching all six main numbers to win a jackpot of at least £1 million, or by matching five main numbers and the bonus ball to secure a fixed £1 million prize.

The jackpot will be shared across both rounds, while all other prize tiers will remain fixed cash amounts, paid for each round. In addition, the Lotto HotPicks add-on game will also move to the new two-round format and will continue to be priced at £1.

Andy Carter, senior winners’ advisor at Allwyn, said: “This is a huge moment for players as we enter a new era for the nation’s millionaire maker, Lotto.

“From now on, every ticket gives you two chances to win for the same £2 price. We’re talking more winners, more excitement and hundreds more millionaires made every year. It really could be you – not once, but twice.”

The new, updated game is expected to more than double the number of Lotto millionaires – from around 140 a year to about 345, while the odds of winning a prize will improve from 1-in-9.3 to 1-in-4.9, operator Allwyn said.

Jackpots will continue to start at £2 million and can roll over for up to five draws, with a must-be-won draw taking place on the sixth.