The arena where Battle Royal matches are conducted has four corners: red, blue, green, and yellow. Each corner has an entrance shaped like a Pokémon's head: the red corner is shaped like Charizard, the blue corner is shaped like Gyarados, the green corner is shaped like Tyranitar, and the yellow corner is shaped like Haxorus.
The player can enter a Battle Royal challenge by speaking to the third receptionist from the left. There are four ranks that can be chosen from: Normal, Super, Hyper and Master, in increasing difficulty. Initially, Normal will be the only rank available. Winning first place in a Battle Royal challenge will unlock the next-level rank.
Each NPC Trainer will use teams of three Pokémon selected at random. As challenges go up in rank, the Trainers battled become progressively stronger.
Each Battle Royal challenge rewards Battle Points (BP) depending on the player's performance and rank entered.
If the player has won their last five consecutive Battle Royal challenges at Master Rank, the Masked Royal will be assigned as the red corner opponent in the next such challenge, and will greet the player at the reception desk before entering the arena. Regardless of the outcome, the win streak will reset to zero after battling against the Royal.
Battle Points (BP) earned in Battle Royal matches may be exchanged at the first, second, and fourth counters at the front entrance to the Battle Royal Dome. The third counter is the receptionist for entering battles.
Battle Points earned in the Battle Tree or from Mantine Surf can be exchanged for prizes at the Battle Royal Dome as well.
When the player first approaches the counter, they will be invited to participate in a Battle Royal with Gladion, The Royal, and Hau. They will automatically participate with the lead Pokémon in their party, and will not be healed before the battle.
The Battle Royal Dome first appeared in Pushing the Fiery Envelope!, where Ash, after witnessing the Masked Royal earning his 20th consecutive Battle Royal victory on TV, traveled to the dome along with his classmates to take part in a special event, where any volunteers would get a chance to battle the Masked Royal. Ash's Litten, having become agitated after seeing the Masked Royal's Incineroar, jumped down from the stands, leading to Ash taking part in a Battle Royal, along with Kiawe and Sophocles.
Incineroar easily shrugged off all of the attacks its opponents threw at it, and was easily able to defeat Kiawe's Marowak and Sophocles's Charjabug with Darkest Lariat. Litten, however, managed to survive the attack, thanks to its sheer determination to battle its evolved form. After the Masked Royal revealed that he had been holding back, both he and Ash decided to get serious. However, this only resulted in Litten getting swiftly defeated by a Bulk Up-powered Throat Chop from Incineroar.
The dome reappeared in A Young Royal Flame Ignites!, where a group of Battle Royal Trainers known as the Revengers, who fight dirty and do not care about the rules, issued a challenge to the Masked Royal to see who was the strongest Trainer at the Battle Royal Dome. The Masked Royal accepted the challenge, inspiring Ash, his classmates, and Professor Burnet to go watch the match the next day. Unfortunately for Professor Kukui, they invited him to be in the audience with them, forcing him to sneak away with the excuse of going for shopping in order to change into his Masked Royal costume and reach the arena just in the nick of time.
When the Revengers once again started playing dirty, Ash's Torracat leaped down from the stands to stop them. The boss of the Revengers, Viren, then entered the stage, and challenged the Masked Royal and Ash to a tag match, with the Revengers Mad Magmar and Mr. Electric facing off against the two, threatening to buy out the dome should they lose to his men. The Masked Royal and Ash accepted the challenge, and Royal gave Ash a mask of his own, making him "Ash Royal". During the battle, where the Revengers continued to ignore the rules and play dirty, Ash's Torracat learned Revenge, using it to defeat both of the opposing Pokémon. Even when Viren tried to force his way, he was easily swept aside by the Double Royals. Before departing, Ash and Royal promised each other to face each other at the dome one day to settle the rivalry between Torracat and Incineroar.
In Helping the Hometown Hero!, Ash, his classmates, Goh, and Chloe visited the Dome, where Ash, Professor Kukui, Kiawe, and Gladion took part in a Battle Royal, held to celebrate Ash's return to Alola. Ash and Professor Kukui were the last two Trainers standing, but the winner was left unrevealed.
In the anime, the Battle Royal Dome also supports Single Battles, in addition to Battle Royals.