The new Government could be formed by any one of a variety of arrangements agreed between parties.
The options include a formal coalition agreement, a confidence and supply agreement or even by a party's preference to abstain on confidence and supply votes which face the Government throughout the year.
If, for argument's sake, New Zealand First agreed to abstain on confidence and supply votes in exchange for a raft of policy concessions by National, National's 58 votes would beat Labour and the Greens' 52 no-confidence votes on crucial votes and allow National to govern.
It is likely a deal with the agreement to actively support the Government on confidence and supply votes would entitle the smaller party to ministerial positions.
Since 2005, Labour and National governments have used this model.