The TVNZ debate at 7pm will be the first time the two square off on the campaign. There is a lot to tackle each other over.
But all Luxon has to do is survive and not give people reason to believe he can’t handle the top job.
Hipkins has to somehow persuade people Luxon is not cut out to be Prime Minister, and try to re-inflate his own standing with voters and get them interested in Labour again.
Thus far both the polls and the mood of the public have shown quite a shrug of indifference to both Chrises.
Ahead of the debate came the smack talk.
Luxon was pretending he was “relaxed” and repeated his claim about Hipkins being a “champion” debater compared to his own high-school efforts. He claimed Hipkins was a “champion university debater” and probably one of the best in the world. Hipkins’ office later clarified that Hipkins did not debate for his school or his university.
Hipkins, meanwhile, was pretending it was just another day, he hadn’t done much practice, he might think about it at some point this afternoon, nothing to see here.
Luxon’s meaning of the word “relaxed” must be different from the dictionary version. He has been doing a lot of training - often retreating for debate preparation after only a couple of hours on the public campaign trail.
Today, both leaders have morning campaign engagements and then disappear to sharpen their lines and do their carbo-loading, their meditation or whatever prime athletes do ahead of big events.
The early weeks of the campaign proper have been training of a kind: the cameras following their every move, getting voters’ reactions to them and the daily interrogations by the media.
So what can we expect? The bingo board will include how many times Luxon accuses Labour of being “all spin, no delivery”, “back on track”, “the turnaround” and how many times Hipkins says “cuts”.
Politicians behave best in their natural environments, and for Hipkins that is in debates and head-to-head situations with his foe.
Hipkins’ challenge will be in showing some of his spark, showing he deserved the high trust ratings that he got in the early months of his premiership. That spark has been a bit missing as he’s trudged around on the campaign trail eating 50 combinations of pastry and meat.
The biggest challenge he faces will be in countering the claims that Labour’s record on delivery on its promises has been wanting - and trying to turn around increasing signs of a mood for change. National is around the 40 per cent mark in the polls while Labour is in the 20s.
It’s already apparent from the daily media interrogations that Luxon is no slouch. His challenge will be in not appearing evasive.
He is not yet adept at undetectably sidestepping a question, but the repeated questions over his tax policy have shown he has developed the skill of simply refusing to answer a question - over and over and over. How that comes across on live television will be interesting to see, as will his response on the question of New Zealand First leader Winston Peters and what National might cave in on, in relation to its potential partners.
The topic in which both men have to triumph is over the cost of living: both how they will get inflation back down, and their offerings to help voters survive until then.
They have very different recipes: National’s tax cuts promise is up against Labour’s shopping trolley of freebies and discounts. It has offered GST off fruit and veges, free ECE for two-year-olds, free prescriptions, free or half-price public transport for younger people, free dental care (eventually) and the expansion of free cervical smear tests and breast screening for women.
So much attention has gone on how National will pay for its tax cuts that it has drawn attention away from how much those $25 a week tax cuts for middle income earners will actually pay for.
The answer to that is not much, although there is a bit more in Working for Families for those who qualify.
We can expect Hipkins to try to persuade people to tally them up and work out whether Labour is actually offering more - and to depict National’s tax cuts as so paltry per person that they are not worth the cumulative cost.
There will also be the inevitable shade-casting over National’s costings: the questions Luxon has struggled so hard to quell.
Usually the first debate is not the best debate. The contenders are nervous and it shows in their performance: they either try too hard or not hard enough.
However, this is also the most important of the three one-on-one debates they will have. It is 90 minutes long - a long time to keep the energy levels up.
People who watch it may not tune in to watch another debate later, barring a drama breaking out on the campaign.
Claire Trevett is the NZ Herald’s political editor, based at Parliament in Wellington.