The Minnesota Vikings are trying to infiltrate the Detroit Lions’ den at Ford Field.

The NFL says all is fair in love and football.

The Vikings have spent nearly $2 million on tickets on the secondary market leading up to Sunday night’s massive game at the Lions in Week 18, according to a report from Sports Illustrated on Saturday afternoon, buying around 1,900 tickets.

The NFL, according to SI’s Albert Breer, says the Vikings did not break any rules by doing so.

The Vikings snatched up tickets behind the Minnesota team bench at about $1,000 each, then emailed season ticket holders, offering the opportunity to buy the tickets at lower prices, “and in some cases for as little as $200 per ticket,” SI reports.

NFL road teams are allotted 600 tickets.

The Lions’ ticket office flagged the odd activity and later learned of the Vikings’ email scheme. The Lions contacted the NFL but were told the Vikings’ tactics were legal.

“As a valued season ticket member, we want to offer you the opportunity to purchase lower-level seats for Sunday night’s game,” the Vikings email reportedly reads, adding tickets must “intended to be used by Vikings fans and not positioned for resale.”

Minnesota also apparently wanted to give families of players and staff a better experience, since the road team’s allotment of seats are often high up and either in the corners or end zones, Breer wrote.

“Given the uniqueness of this game, we wanted to offer our stakeholders—staff, family, season ticket members and team partners—an opportunity to attend,” Vikings spokesman Jeff Anderson said in a statement, per SI.

It makes for even more intriguing storylines ahead of the biggest game of the NFL regular season. Never have teams with this many wins — both the Lions and Vikings are 14-2 — met before the playoffs. And there is so much on the line.

A Lions win or tie would give them the NFC North Division title and No. 1 seed, a first-round bye and homefield advantage through the conference championship game.

The game’s loser will fall all the way to the 5-seed and start the playoffs on the road facing a far more daunting task in an effort to reach the Super Bowl.

Neither team has ever won a Super Bowl, while the Lions are the lone NFC team never to even reach the game.

The Lions defeated the Vikings in Minneapolis in Week 7, 31-29, on a last-minute field goal.