Ricki Herbert will be hoping his team can win through to the World Cup without the need to search the rule book.
In two-legged play-offs there is the provision for the "away goals rule" to be used as a tiebreaker but ascertaining just how it is implemented can be confusing.
First used in the Uefa Cup Winners Cup in the 1965-66 season, the rule has been invoked many times since - as recently as last month's deciding tie in Riyadh when Bahrain got through against Saudi Arabia.
The teams played out a 0-0 draw in the first leg in Bahrain. In the second, Bahrain scored in the last seconds of stoppage time to snatch a 2-2 draw and go through on away goals.
But had the game ended 2-1 to Saudi Arabia after 90 minutes, Saudi would have qualified. The actual result would have decided it with no provision at that point for considering any away goals.
But many question how the rule is interpreted in extra time, ie if both ties had been drawn 0-0 or 1-1.
Some insist away goals should still count double which would mean the home team in the second leg would need to score twice to take the game to a penalty shootout or three times to win.
Others say it is a stand-alone period with no provision for double-counting away goals, while opponents of the rule point to some anomalies.
The All Whites can do themselves a favour by scoring at least once tomorrow and then hope there is no need to reach for the rule book during the return leg in Wellington on November 14.
