BattlEye is one of the most widely deployed anti-cheat systems in PC gaming, and if you play multiplayer titles you have almost certainly run it.
Where you'll find it
BattlEye protects a long list of major games — among them PUBG, Rainbow Six Siege, Escape from Tarkov, DayZ, ARMA and Destiny 2. Developers license it rather than build their own, which is why the same anti-cheat shows up across studios.
How it works
BattlEye runs as a kernel-mode driver that loads with the game. From that vantage point it can inspect memory, watch for code injection, scan for known cheat signatures and verify that the game's own code has not been tampered with. It also performs hardware checks and reports identifiers back to its servers.
Bans are hardware-aware
A BattlEye ban is not just an account flag. The service records hardware identifiers at the time of the ban, so creating a fresh account on the same machine can result in the new account being banned as well. This is what players mean by a "HWID ban."
What it can and cannot read
From kernel mode BattlEye sees a great deal: disk and network identifiers, the Windows machine GUID, motherboard and SMBIOS data. Some of those values live in software and the registry; others are written into firmware. The firmware-resident ones — the SMBIOS UUID, the BIOS serial — are exactly the values ordinary software cannot rewrite, which is an honest limit worth knowing before you assume any identifier can simply be changed.
The takeaway
BattlEye is mature, well-funded and shared across the industry. Understanding that it operates at the kernel level — and that its bans attach to hardware, not just accounts — is the realistic starting point for anyone researching how these systems behave.