Nintendo has blocked an independent Super Smash Bros tournament due to the organisers' use of mods and, according to the platform holder, illegal copies of the game.
The Big House is an annual US Smash Bros fan convention that's been running since 2011. Due to the coronavirus pandemic, the 2020 event was set to take place online, running from December 4 to 6.
The tournament was to focus on Switch title Smash Bros Ultimate and fan favourite GameCube outing Smash Bros Melee. The latter launched without online functionality, which means tournaments often have to rely on Dolphin, a GameCube and Wii emulator, with fan-made modifications.
One such mod is Slippi, which was released earlier this year and improves the online infrastructure in a way that makes it smooth enough for competitive matches. The Big House intended to use this, but Nintendo of America issued a cease and desist order to block the event.
"We were informed we do not have permission to host or broadcast the event, primarily due to the usage of Slippi," the team said in a statement via Twitter. "Sadly, all our competitions are affected.
"We are forced to comply with the order and cancel The Big House Online for both Melee and Ultimate. Refund information will be sent shortly. We apologise to all those impacted."
In a statement to Kotaku, a Nintendo spokesperson said the company "appreciates the love and dedication" for Smash Bros among the fighting game community, and highlighted that not only has it partnered with various tournaments -- both online and offline -- in the past, but will continue to do so in the future.
In this instance, it was the "use of illegally copied versions of the game" as well as Slippi that Nintendo took issue with. The spokesperson claims Nintendo asked the tournament organisers to stop this.
"They refused, leaving Nintendo no choice but to step in to protect its intellectual property and brands," the statement concluded. "Nintendo cannot condone or allow piracy of its intellectual property."