Maciej “Groobo” Maselewski held the Diablo speedrunning record for years, with a 3-minute, 12-second Sorceror run that seemed almost unbeatable due to powerful glitches and luck. However, a team of other speedrunners used analysis tools and software to investigate Groobo’s run, discovering inconsistencies that raised doubts about its legitimacy.
The team, led by Allan “DwangoAC” Cecil, conducted an automated search through billions of legitimate Diablo dungeons to verify the authenticity of Groobo’s record-breaking run. They found several issues, including a sequence of stairways that appeared too closely together and a lucky find of Naj’s Puzzler on level 9.
“We were driven by curiosity and resentment,” Cecil said. “We wanted to replicate the luck and speed that Groobo achieved.” The team used tool-assisted speedrunning (TAS) techniques, which utilize outside tools to improve performance, to replicate Groobo’s run or similar runs every time.
The investigation revealed that Groobo had likely relied on exploiting game glitches and system timing to seed random number generation (RNG), rather than relying solely on human luck. This raised questions about the ethics of using such methods in competitive gaming. The scandal highlights the importance of verifying the authenticity of records and performances in speedrunning communities.
Source: https://arstechnica.com/gaming/2025/02/the-diablo-hackers-that-debunked-a-record-speedrun