Last weekend some fans were turned away from the Wellington Sevens at Westpac Stadium after they were breath-tested by security staff.
Westpac Stadium chief executive Shane Harmon said breath tests were only used to confirm whether someone was drunk.
There will be 31 games with nine-minute halves this weekend.
Teams will be vying for $2.6 million in prize money.
Stadium bars will open one hour after the gates open on both days and the number of drinks available for purchase will vary in accordance with liquor licence guidelines or general levels of behaviour, the Eden Park spokesman said.
Patrons will be able to purchase four drinks per person at a time to start with. The amount will be closely monitored by the stadium alcohol management team over the course of the day. The ground also has a dedicated "chill out" area for people needing a break and free water bottles will be given away on arrival.
Meanwhile, police have said that although they want people to have a good time, they encourage those attending the event to drink responsibly and not spoil the event for others.
National manager of alcohol harm reduction, Senior Sergeant Andy Smith, said security arrangements for the Nines were the responsibility of the event and venue organisers, but that police continued to work closely with them to help ensure a safe and enjoyable event.
"We also want people to make good decisions about getting themselves and their friends home safely. This includes not drinking and driving, or, if drinking, making alternative transport arrangements or nominating a sober driver."
Getting there and back
Today:
Gates open at 11.30am
Opening ceremony at 12pm
First game kicks off at 12.30pm
Last game kicks off at 7.35pm
Sunday:
Gates open at 10am
First game kicks off at 10.35am
Final game kicks off at 6.40pm
Presentation at 7pm
Transport
There will be free travel to and from Eden Park on trains and special event buses - for holders of pre-purchased game tickets including those on mobile devices. Buses will operate from the city centre, Northern Busway stations, Manukau, Botany, Pakuranga, Newmarket, Mt Eden, Takapuna. Free trains will operate from two hours before start.
For the timetable go to At.govt.nz/bus-train-ferry/events/downer-nrl-auckland-nines/