Here, Press Association Sport delves into the subplots ahead of a French Riviera clash with Robert Lewandowski and the Poles.
IS KYLE LAFFERTY FULLY FIT?
He says so. The signs were certainly encouraging when Lafferty, after tweaking his groin at training on Tuesday, went through drills on Friday. However, doubts remain over whether the 28-year-old can truly be at full capacity so soon after the scare. He completed 90 minutes just twice last season and has started and finished a game only once since September 7.
IF IT'S 5-3-2, WHO OCCUPIES THE FLANKS?
The three-man defence that Michael O'Neill has experimented with in recent friendlies suggests that will be the system facing Poland. Craig Cathcart, Gareth McAuley and Jonny Evans are nailed on for those spots but it is less clear who will be the two men flanking them. On the left, Stuart Dallas is in good form but Shane Ferguson is perhaps a better option defensively. On the right, the desire to find a spot for Manchester United's Paddy McNair could relegate Fleetwood's Conor McLaughlin to the bench.
CAN NORTHERN IRELAND STOP ROBERT LEWANDOWSKI?
A 13-goal haul in qualification, which included two against Scotland and a further strike against the Republic of Ireland, ensured Lewandowski equalled Northern Ireland's own David Healy's record for the most goals in a Euros qualifying campaign. While the only goal Northern Ireland have conceded since qualification was a penalty in Wales, they know Lewandowski will pose the biggest threat since Cristiano Ronaldo scored a hat-trick at Windsor Park in 2013.
WILL CONOR WASHINGTON GET THE NOD?
Four years ago, Washington might have missed the late Euro 2012 kick-offs because he had to rise early to deliver post. Now, the QPR striker, who has scored twice in four internationals, has catapulted himself into O'Neill's thinking. There are doubts over whether he is a good foil for Lafferty, though, which means the hard-working Jamie Ward could start instead. It's a welcome conundrum for O'Neill, who also has Will Grigg and Josh Magennis in his attacking arsenal.
HOW WILL NORTHERN IRELAND COPE WITH THE OCCASION?
This is an experienced squad but none of them have ever experienced an international tournament before and that brings a hype and excitement which O'Neill has had to manage. The fact clashes with Poland and Ukraine arrive before they face the Germans in Paris means their fate will likely be decided in the first two contests. The belief Northern Ireland can qualify from this group has only been heightened by a 12-match unbeaten run, a streak longer than any other country at Euro 2012. A nation expects...kind of.