Diablo 4 has, once more, had to disable trading due to a duping bug—the third time in one year, albeit just barely, as announced on the Diablo 4 forums by community manager PezRadar:
"We will be disabling trading in Diablo IV while we investigate a possible duplication issue. We apologise for the disruption and will provide updates on when we will have trading available again once we further investigate and identify any issues we need to resolve."
What I find mathematically pleasant and auspicious about this occasion is that two dates almost match exactly, like an anniversary—it is August 15, 2024, and Blizzard suspended all trading activity yesterday. On August 15 2023, the company had to do the exact same thing. A similar suspension occurred in October 2023, making this the third time in a single year it's happened—in fairness, just barely.
The dupe, as outlined by YouTuber Sliver of Time, was first properly broadcast on streaming website bilibili (thanks, GamesRadar)—appearing to weaponise the player stash and the power of friendship. I should note for those keen to replicate this for themselves that duping items like this is against the EULA, which decrees that players shall not "create, utilise or transact in any in-game item created or copied by exploiting a design flaw, undocumented problem, or program bug in the Platform."
As for why these duplication bugs are a problem—live service and MMO economies are a fragile thing. Any vulnerability that lets RMT websites continue to ply their unscrupulous trade runs the risk of ramping up prices beyond all reasonable recognition. Take Star Wars: The Old Republic, for example, which had low-level gear going for millions and millions of credits last year.
Blizzard stepping in and slamming the emergency bunker door shut makes sense, regardless of whether or not the dupe is widespread enough to've had an impact. Developers can suss out the exact nature of the glitch later, but for now, quarantining the economy makes sense—the cut's already been made, time to stop the bleeding.
Still, the fact this is a routine enough problem to warrant a national holiday is frustrating. As one player notes on the game's subreddit, nothing is certain but "Death, taxes, and trading disabled in D4." Which is a shame, because according to PC Gamer's own Tyler Colp, this season's been pretty dang good otherwise.