If you have played MMOs or shooters that originated in South Korea, you have almost certainly run nProtect GameGuard — and possibly its rival XIGNCODE3. They represent an older, deep-running style of anti-cheat.
What GameGuard is
nProtect GameGuard is an anti-cheat developed in South Korea and bundled with a long list of Asian online games. It loads alongside the game with a low-level driver, hides the game process from tampering, scans memory for cheats and blocks tools that try to attach to the game.
A deep, intrusive design
GameGuard is known for running deep in the system — historically at a level and with techniques that resemble what security software calls a rootkit, in the sense of operating below normal visibility. That design makes it effective at spotting cheats, but it has also given GameGuard a reputation for being intrusive: conflicts with other software, false positives, and being difficult to fully remove have all been long-standing community complaints.
XIGNCODE3 and the wider category
GameGuard is not alone. XIGNCODE3, from a different vendor, fills the same role for many other games and works on similar principles. Together they define a category — deep, driver-based anti-cheats common in the Asian gaming market, predating the current wave of Western kernel anti-cheats but conceptually related.
What it means for players
For players, the practical points are: these anti-cheats run with high privileges, they can conflict with other low-level software, and they collect system and hardware information as part of detection. Keeping drivers updated and not running memory tools alongside the game reduces friction. Bans follow the game's own policy, layered on top of GameGuard's detection.
The takeaway
GameGuard and XIGNCODE3 show that deep, driver-level anti-cheat is not new — the Asian MMO market has used it for years. They are effective but intrusive, and they are a useful reminder that today's kernel-anti-cheat debate is the continuation of a much older one.