The Wild Card Round is the first round of the playoffs in which four teams from each conference compete. The winner of each game advances to the next round, the Divisional Round.
In the Wild Card Round, the two division winners with the best records host the two wild card teams with the worst records. The team with the better record hosts the game.
For example, if one division winner has a 14-2 record and another division winner has an 11-5 record while both wild card teams have 10-6 records, then the 14-2 division winner would host one of the wild card teams while 11-5 division winner would host other wild card team. If both division winners have identical records, then seeding will be used to determine home field advantage.
The format for this round was implemented in 1994 when NFL expanded from 28 to 30 teams with addition of Carolina Panthers and Jacksonville Jaguars. Before that only three rounds were played in NFL playoffs and all four playoff games were hosted by division winners.