The 1922 committee of Tory backbenchers confirmed last night that the new party leader - and prime minister - will be elected on September 5.
Eleven candidates have so far announced that they want to succeed Boris Johnson in Number 10.
So what are the rules which will determine how that unwieldy number will be whittled down to the one who claims the crown?
Twenty Is The Magic Number
To even get on the ballot paper, would-be leaders need the support of at least 20 of their fellow MPs by 10pm tonight.
So far, the only ones to hit that number are Rishi Sunak, Penny Mordaunt, Tom Tugendhat and Nadhim Zahawi.
All of those with the requisite support will go forward to Wednesday’s ballot of Tory MPs.
Tory Squid Games
OK, this is where it gets pretty brutal.
Anyone who fails to get at least 30 votes in the first ballot are automatically kicked out of the race.
This is much harsher than previous contests, when only the candidate coming last dropped out.
Critics say the new rule is particularly unfair on less-prominent candidates.
But party bosses say that, given the large number of candidates, a swift cull is needed to stop the race dragging on and on.
Never Mind The Ballots
All of those who survived the first round of voting will go forward to Thursday's ballot, where, once again, the candidate coming bottom - plus those who failed to win the support of 30 MPs - will be eliminated.
This process will continue until only two hopefuls are left, with the aim being that this point will be reached before MPs go off for their summer recess on July 21.
Battle Of Hustings
A series of leadership hustings will take place around the UK over the summer to give Tory party activists the chance to grill the final two candidates on the big issues.
Ballot papers will be sent to around 200,000 Conservative members, with the person receiving the most votes being announced the winner in time for MPs returning to the Commons in eight weeks' time.