You open League of Legends and instead of the game you get a Vanguard message, or the game won’t launch at all. Vanguard is the anticheat Riot rolled out in LoL, and without it you can’t get into the game these days. It runs at the kernel level of your system, though, which makes it both the most effective and the most controversial part of the client. This article explains what Vanguard does, why Riot introduced it, what it requires from your computer and what to do when it stops the game from launching.
What Vanguard is and why Riot introduced it
Vanguard is Riot Games’ own anticheat system, first deployed in Valorant in 2020. It arrived in League of Legends four years later, in 2024 (the 14.9 patch cycle). One of the triggers was a 2023 security incident in which the source code of League of Legends and other Riot games leaked. After that, the company tightened its protection against unauthorized tampering with the client.
The reason Vanguard exists is simple: classic anticheats that run as a regular application next to the game are getting easier and easier for cheat software to bypass. That’s why Vanguard works at a much deeper level of the system, in the Windows kernel rather than just “next to” the game, so it can also detect tampering that happens outside the League of Legends process itself.
How Vanguard works under the hood
Vanguard has two parts. The first is a kernel driver that loads as soon as Windows starts and checks whether the system is in a trusted state, meaning nobody has tampered with the boot process, loaded a vulnerable or unauthorized driver and so on. The second part is a user-mode application that actively monitors the game itself once you launch it.
On macOS, Riot uses a different, so-called “embedded” version of Vanguard. It runs only at the application level, without a separate kernel driver, because macOS technically requires a different approach than Windows. Linux isn’t supported by Vanguard at all, so League of Legends can’t be launched through Wine or Proton (typically used on the Steam Deck and Linux distributions).
What Vanguard requires from your computer
For Vanguard to verify your system as trusted, it needs specific security features enabled at the hardware and firmware level:
- TPM 2.0: a chip (or its software equivalent, fTPM/PTT, built into the CPU) that can provide a signed attestation of the firmware state and early system boot.
- Secure Boot: a UEFI feature that prevents unauthorized software from loading while the computer is starting up.
- UEFI mode: Vanguard doesn’t support older BIOS without UEFI.
- IOMMU: hardware protection of device access to memory, which Vanguard uses among other things against so-called DMA cheats (cheating via external hardware connected to the computer’s memory).
In practice, this means that on ordinary PCs built in roughly the last ten years, these features exist in the BIOS but are often disabled by default. On older builds without a TPM 2.0 chip or UEFI support, League of Legends won’t launch at all. That’s not a bug, it’s a hard requirement.
Why Vanguard might stop the game from launching
The most common cause is that one of the features above is disabled in the BIOS, typically Secure Boot or TPM. The second common cause is that the Vanguard service (VGC) isn’t running in the background or didn’t start properly, which often happens after a Windows update or after your antivirus interferes. The third possibility is running the game in a virtual machine or over remote desktop. There, Vanguard by design can’t verify that the system is trusted, so it refuses to let the game run.
How to check the TPM and Secure Boot status on your computer without touching the BIOS:
- Press Windows + R, type tpm.msc and confirm. A window opens showing the TPM chip status and its version.
- Press Windows + R, type msinfo32 and confirm. In the system summary, find the “Secure Boot State” line, which tells you whether it’s on.
If one of the features is disabled, you can enable it in your computer’s BIOS/UEFI settings (usually with the Del or F2 key right after powering on, before Windows starts loading). The exact location of the options varies by motherboard or laptop manufacturer, so follow the manufacturer’s instructions. Changing BIOS settings carelessly isn’t worth the risk. If you’re not sure what an option does, stick to the manufacturer’s guide rather than clicking around blindly.
Vanguard: On-Demand mode
For a long time, the Vanguard driver ran constantly from the moment Windows started, even when you didn’t have League of Legends open at all. That was one of the main targets of criticism. In June 2026, Riot changed this behavior by introducing On-Demand mode: on computers that meet a stricter set of security requirements (Windows 11 25H2, Secure Boot, TPM 2.0, IOMMU, Virtualization-Based Security and Hypervisor-Protected Code Integrity), the driver loads only when you launch the game and shuts down again after you quit. According to Riot, roughly a third of players met the requirements for this mode at launch; the rest had to enable the relevant features in their system manually.
In other words: if you have a newer Windows 11 and all the features mentioned enabled, Vanguard no longer runs in the background all the time, only while you’re playing.
The controversy around Vanguard
Vanguard is controversial for good reason, and it’s worth explaining why instead of glossing over it.
The main objection concerns the scope of access: software running in the system kernel theoretically has access to everything happening on the computer, not just League of Legends. Critics compare it to rootkit-like behavior, not because Vanguard is malicious, but because the technique it uses is the same one malware uses, and a bug or vulnerability in code running in the kernel can crash the whole system, not just the game. Riot responds that Vanguard collects only the data needed to detect cheating, but independently verifying what closed-source code running in the kernel actually does isn’t easy.
The second recurring topic is Riot Games’ ownership by the Chinese company Tencent and concerns about whether anyone other than Riot could access Vanguard data. Riot says no and that it collects only the minimum needed to detect cheats, but it’s a concern that can’t be technically verified from the outside.
Another incident followed in May 2026: a Riot update to Vanguard stopped so-called DMA cheats from working. These are external devices costing thousands of dollars that connect to a computer’s memory and read game data from it. At the time, the company posted a photo of the disabled devices on social media with a comment about a “$6,000 paperweight”, which part of the community took as a threat that Vanguard could permanently damage ordinary hardware. Riot then explained that the update targeted only specific cheating devices connected via SATA/NVMe and that Vanguard can’t and doesn’t intend to damage legitimate components or the whole computer. It only renders specific cheat hardware unusable while the IOMMU protection that LoL and Valorant require is active.
To sum up the controversy: Vanguard is more invasive than most anticheats, and that’s a fact, not an exaggeration. At the same time, there’s no evidence of malicious behavior toward ordinary players. The risk comes from the fact that anything running in the system kernel inherently has a wider reach than software outside the kernel. Whether that trade-off is acceptable to you in exchange for fewer cheaters in your matches is your call. What definitely makes no sense is trying to get around Vanguard by disabling Secure Boot or using third-party software. You risk both system stability and an account ban, because Riot treats bypassing the anticheat as cheating regardless of the reason.
Vanguard is shared across Riot games
Vanguard isn’t exclusive to League of Legends. Riot first deployed it in Valorant in 2020 and gradually extended it to Teamfight Tactics, Legends of Runeterra and 2XKO. That means two practical things: the TPM 2.0, Secure Boot and UEFI requirements are the same across games, so once you meet the conditions for League of Legends, you meet them for the other Riot games too. And if you have Vanguard installed for one game, you don’t need to install it again for another. Both the installation and the background service are shared across the whole Riot Client.
What to do when Vanguard won’t let the game launch
A quick checklist before you move on to deeper troubleshooting:
- Restart your computer. A restart alone fixes a large share of Vanguard service problems.
- Use tpm.msc and msinfo32 to check that TPM 2.0 and Secure Boot are enabled (steps above).
- Check in Task Manager or services.msc that the Vanguard service (VGC) is running and set to start automatically.
- Make sure you’re not running the game in a virtual machine, over remote desktop or in a sandbox. Vanguard deliberately blocks the game there.
- If none of that helps, reinstall Vanguard through the official Riot Client or the Hextech Repair Tool.
Specific Vanguard error codes and exactly what to do for each one are covered in the article most common LoL launch errors.
FAQ
Yes. Since its rollout in 2024, Vanguard has been a mandatory part of the LoL client and you can’t get into the game without it.
There’s no documented malicious behavior toward ordinary players, but it runs in the system kernel, which inherently means wider access and a bigger risk if a bug appears in the code. It’s a trade-off between protection against cheaters and the scope of access the software gets.
There’s no Vanguard for Linux, so the game won’t launch through Wine or Proton. On macOS, a different, less invasive version of Vanguard runs without a kernel driver.
It’s a security chip (or its software equivalent) that can provide signed confirmation that the system booted in a trusted state. Vanguard uses this information to verify that nobody has tampered with the boot process.
It used to, and that was one of the main targets of criticism. Since June 2026, on computers that meet stricter security requirements (Windows 11 25H2 and other features), Vanguard runs only while you have the game open.
No. The May 2026 update blocked only specific cheating devices connected to the computer’s memory, not players’ ordinary hardware. Riot has publicly ruled out damaging legitimate hardware.
Information verified as of 27 August 2026, for patch 26.18. Specific error codes and their fixes are in the article most common LoL launch errors, how to download and install the game is covered in the download and installation guide, and what to do about ping and connection issues is explained in ping, lag and connection in LoL. Where you can play LoL and which language to choose is in the article language, EUNE and servers. The full champion overview is in champions in LoL, and the whole hub is in the League of Legends section.