National came out on top with 46 per cent of the vote and 58 seats. Meanwhile, Labour finished with 35.8 per cent of the party vote, giving them 45 seats.

A total of 2,179,668 votes were counted on Saturday, and a further 384,072 special votes are expected to be counted. Voter turnout is estimated to be 78.8 per cent, compared with a final 77.9 per cent turnout of those enrolled in 2014.

A total of 61 votes in the 120 seat Parliament are needed to form a government, or a majority of the votes cast if there are any abstentions.

That means neither major party can be sure of a majority alone based on the results so far. This is where things get complicated.

Under MMP, the party leader who can command a majority in Parliament gets to govern. These results have thrown up a few different options. And while none of them are ideal, as the leaders have said throughout the past couple of weeks: they have to work with what voters give them.

So what are the possible coalition options?

At this stage, it's highly likely National will come back for a fourth term with the help of NZ First.

Winston Peters' party won nine seats. So with National's 58, that takes then across the line to 67 seats.

NZ First has worked with National before, and while there are some National policies Peters doesn't agree with, that doesn't mean he won't agree to form a coalition.

Peters hasn't pulled any punches when attacking Bill English's National Government. However, he was also highly critical of Jim Bolger in 1996, before joining National in a coalition and stepping into the roles of deputy prime minister and treasurer. 

ACT's David Seymour could be part of a coalition with National but it's likely ACT will find itself frozen out, but will almost certainly back National anyway on key confidence and supply votes. 

Peters and Seymour have said they won't work together. However, ACT won't go against National to work with Labour.

Seymour won his Epsom electorate, giving ACT one seat in the House. The party only took home 0.5 per cent of the party vote, meaning no other ACT candidates made it in. While his preference is to work with National, Peters might stand in the way.

Labour couldn't form a majority government with its ideal coalition — Labour and the Green Party. Together they have just 52 seats.

But with the help of NZ First, they could just make it, with 61 seats.

Labour leader Jacinda Ardern has said she would prefer a simple coalition, which was why she and Bill English both encouraged Kiwis to "cut out the middleman", as English put it.

But under MMP they have to work with what the voters deliver, meaning Peters could end up working with the Greens despite clashing with them throughout the campaign.

It's an outside chance, but with 58 and seven seats respectively, National and the Greens could technically form a coalition government.

James Shaw has campaigned for a change of government throughout 2017, and the two parties' environmental policies don't line up.

But Shaw said if English called the Green Party would be "duty-bound to listen to what he has to say".

In order for the Greens to put politics aside and go with National, English's offer would have to be pretty good, he said.

Together Labour and NZ First don't have the numbers to form a majority government. 

However, they could potentially form a minority government with the support of the Green Party. In this scenario the Green Party wouldn't be part of an official coalition but they would work with the government, and help stop the Opposition parties toppling them with a motion of no confidence. 

Similar to the above scenario, if neither National or Labour can form a majority coalition government, National could govern alone as a minority.

However, if Peters, or others, decide they don't like what National's doing they could call for a vote of no confidence and topple the government.

It's unlikely, almost unthinkable, but it is technically possible.

When the two major parties form a government, it is referred to as a grand coalition.

The approach has been used in modern Germany and twice in times of crisis in New Zealand — once during WWI and once during the Great Depression.

At the end of the day, it's likely to come down to what Peters decides to do.

"All roads will lead to Russell," he said on Saturday night at his election party in the Bay of Islands.

And as Ardern said on Saturday night: "The final outcome of tonight's election will not be decided by us, it will be decided by MMP."

It could take another two to three weeks before we know who will form the next government.

The official results, which also take into account the estimated 384,072 special votes, are due on October 7, with the return of the writ and declaration of list MPs to be issued on October 12.

 - Stuff