A second-hand processor can lock a player out of several online games — not because the hardware is faulty, but because its previous owner cheated with it.
A case reported on Reddit describes exactly that: someone installed a used AMD Ryzen 7 5800X3D in their PC and was thrown out of the tactical shooter Valorant the moment they first launched it. Riot Games support confirmed that the previous owner had cheated, so the CPU sits on an internal blacklist. According to the buyer, the entry appears to have dragged other components such as the motherboard along with it once installed. Riot does not remove such entries by hand.
Valorant is not the only affected title. Every PC game from the studio is covered: League of Legends, Teamfight Tactics, Legends of Runeterra, 2XKO and, presumably, future releases.
The mechanism behind it is Vanguard, Riot's own anti-cheat system. By default it runs deep in Windows' kernel mode and requires an autostart; if it crashes there, players must reboot to keep playing. Only in June 2026 did an update soften the autostart requirement: players who enable, among other things, a Trusted Platform Module (TPM), Secure Boot and memory integrity features may start Vanguard alongside a match instead.
How Riot uniquely identifies processors is unclear. CPUs report only their model to the operating system — one Ryzen 7 5800X3D is not readily distinguishable from another. Hardware fingerprints built from clock behaviour and voltages are conceivable, since every chip behaves slightly differently. From a studio's point of view, an identification hash stored in the TPM would be simpler: because the TPM usually sits inside the CPU as a coprocessor, the hash would survive a move to a new PC, and Riot certainly has TPM access in the match-start mode.
A historical parallel is hard to miss: Intel's Pentium III carried a unique serial number from 1999, which triggered protests from privacy advocates who warned it worked like a permanent cookie.
For buyers of second-hand hardware the lesson is that a component's past is now part of its risk profile — and for the resale market, a hardware fingerprint becomes an invisible defect that ships with the part.
