ArenaBowl XXXI was the championship game of the 2018 Arena Football League season.
The playoffs consisted of a two-game home-and-home semifinal series with the winners determined by aggregate score.
With one week remaining in the 2018 regular season and a then three-way tie for first, the league announced the ArenaBowl would be hosted by the semifinal winner with the higher average attendance through the season instead of using any tiebreakers or home field advantage based on records.
Once the semifinals were completed, contrary to the previous league statement on the host team, the higher-seeded Baltimore Brigade, not the higher-attended Washington Valor, hosted ArenaBowl XXXI at Royal Farms Arena.
The Valor's home field, Capital One Arena, had already scheduled summer renovations to begin at that time.