Two days before its official release, pirated versions of the hotly anticipated Super Mario Party have leaked online, highlighting Nintendo’s struggle to fight piracy on the Switch.

The game—in two different file formats—is being widely shared on torrent sites, in piracy-focused Discord channels, and in gaming mod forums, where people talk about how to modify their consoles to play homebrew, unlicensed, and pirated games.

Motherboard has independently confirmed that the files being circulated contain a working version of the game, and has seen video of it running on a modified Nintendo Switch. We have not been able to determine how the game initially leaked or who first uploaded it (journalists have had review copies of the game for at least a few days now, though there’s no indication that any journalist leaked it.)

A photo of a Switch running a pirated version of Super Mario Party. Image sent to Motherboard by a source who downloaded it.

It’s rare for Nintendo games to leak before their release date. Versions of last year’s The Legend of Zelda: Breath of the Wild and 2016’s Pokemon Sun and Moon apparently leaked to small audiences, who posted videos and screenshots online. Those leaks do not appear to have been widely available to the console-modding community. By contrast, Super Mario Party is being traded in Google Drive links and crucially, in a torrent file with hundreds of seeders. The game will only work on a Switch that's been hacked or modded, but there are plenty documentation created by the hacking community that makes it easy, meaning there’s no easy way for Nintendo to stop its spread.

"WHAT," one user on a Discord channel said of the leak. "This is c r a z y."

Nintendo did not respond to a request for comment.

Piracy has been a particularly stubborn problem on the Nintendo Switch, which is easily modifiable to run games and files that Nintendo didn’t intend it to. There are many legitimate reasons to jailbreak a video game console—modding the Switch allows greater customizability, the ability to side load bespoke apps, and the ability to play home-brew games.

The game running on a modded Switch.

But one of the most popular reasons to jailbreak a Switch is to play pirated ROMs, which Nintendo has been increasingly trying to remove from the internet. As Nintendo steps up its enforcement of its intellectual property, it’s also forcing ROM sites to delete games that are no longer sold and cannot otherwise be acquired. There's no "I can't find it anywhere else" ethical argument to be made with Switch games, especially not ones that haven't even been released yet.

Nintendo has tried to discourage people from modding their Switch consoles by issuing software updates that can ban people's Switch consoles from connecting to the internet. Sony and Microsoft have largely prevented piracy by requiring frequent system updates and stable internet connections to play games (and which can check a game’s authenticity.) Part of the appeal of the Switch, on the other hand, is that it’s portable, and most of its best games can be played anywhere offline. Any requirement moving forward that’d require the Switch to be connected to the internet to play would be a serious bummer.