There are two ways to do election night. By far the easiest and most sensible is just to go to bed as usual and wake up to a pretty clear picture about the results and who'll be forming the next government.



The other involves spending an exhausting all-nighter frenetically trying to work out, for example, what a 2,000-vote change in the majority of Putney at 12:30am might mean for other seats, and for the next parliament.

To those in the first group: You're making a wise choice. To those in the second: This post is for you. Here's a through-the-night guide to what to look out for, what it all means, when the seats will declare, and what mistakes to avoid.

The bigger picture.

First, it's best to think about the different scenarios we're looking out for on the evening, so we can think about which world we're living in. There are four to watch for:

1. Conservative majority of 50-plus – "May's gamble pays off": Any result that gives Theresa May a substantially increased majority will look like she made the right decision to call an early election, even if the Tories’ weak campaign does lasting damage to her team’s reputation for competence. Jeremy Corbyn, meanwhile, could face yet another challenge for leadership of the Labour party. This is, if you believe the polls, still the most likely scenario, if only just.

2. Conservative majority of up to 30 – "Status quo": This starts to look bad for everyone: Labour would have failed to break through, despite the hype in the later stages of the race, while May would have failed to "strengthen her hand" – despite claiming this was essential for a successful Brexit. The damage to her authority in this scenario could prove politically fatal. This is the second-most plausible scenario.

3. No overall majority – "Chaos": This scenario is still a fairly unlikely one with polls where they are, but it is definitely possible. Depending on which is the largest party (most likely the Conservatives) and the other numbers, the best (if slim) chance of forming a government could be Labour, SNP, and possibly the Liberal Democrats reneging on their pre-election promises and coming to some (formal or informal) arrangement. If they don't manage that, this could even result in a second 2017 general election. Ooof.

4. Labour majority – "Black swan": Barring an SNP collapse – of which there's no sign – Labour need a national vote share of about 7 points more than the Conservatives just to be the largest party. They need a lead of around 10 to 13 points to have even a small majority. Even the best poll for Labour shows a 1-point Tory lead, meaning the polls would need to be wrong by more than 10 points in Labour's favour – and almost every polling error in recent history has been in the other direction. Still, though, recent history has delivered no shortage of shocks, so we've included this one just in case.

10pm – The exit poll.