Can lichess detect cheating? (Finally answered!)

Lichess still hasn’t given an official statement about their anti-cheating detection system. Some lichess moderators have come out and said that they rely on a strong engine to detect a potential computer user in-game. Also, lichess allows manual reports to identify cheaters.

Lichess is one of the biggest platforms when it comes to playing chess online alongside and chess24, I think that if you are interested in chess you might have heard about before.

One of the questions that come from the users of this platform is how it actually detects players who cheat? The moderators are not upfront about this and the fanbase wants to know.

If you are one of the users of lichess then you would want to know how they actually detect players who use computers in their games. 

That is what this article is about, their detection system, I am going to provide a full explanation. Without further ado, let’s get started. 

There is an anti-cheating detection system in lichess

There is a cheating detection system in characterized by an auto in-game abort with the message “cheat detected” which means the user will be banned instantly.

We are talking about one of the biggest chess platforms ever, even though they are not commercialized (they’re only monetized by donation) they would of course need to take measures against cheaters.

Cheaters make every chess platform experience bad, but unfortunately there is no sure-fire way to get rid of them. Lichess, like most chess platforms, is pretty accessible.

Cheaters can easily get to the platform since statistically speaking, it is just bound to happen. The anti-cheating detection system of lichess is characterized by the auto-abort “cheat detected” message.

This will trigger easily if the computer that the cheaters are using are from the lichess platform itself, or the chess engine that is monitoring the games found an unusual amount of best moves played in the game.

It is important to note that this doesn’t trigger all the time, but it does happen every now and then.

Lichess detect cheating by using a strong chess engine

In most chess servers the games are observed by a strong chess engine like Stockfish, and it constantly evaluates if the percentage of moves made by the players are identical to its top choices. 

This is likely the cheating detection system implemented in lichess. It is unclear if this is the only cheating detection system that lichess implements and if there is more, but they likely use this.

A strong chess engine will monitor the games, and if it has found that one of the players consistently played the top 1 best move then it will trigger the auto-abort message.

There is an obvious loophole in this though, which is that you just don’t want to play the absolute best moves in the position and mix it up while still winning the games. 

There’s been a lot of observation that lichess’ anti-cheating detection system is not really that reliable since there is a way around it. But still, they do have it even if you haven’t experienced it yourself.

Examples of the faulty anti-cheating system in lichess

There are many examples of people playing with a chess engine on and getting away with it. There is a detection system but it is not very trusted.

Just from looking on forums that exist online, it seems that almost everyone is sure that there is an unreliable cheating detection system. It seems that lichess is not very efficient in this aspect.

There are also a lot of titled players on youtube that are absolutely sure their opponent uses a computer even manually reviewing it themselves, yet lichess wasn’t able to detect them automatically.

They do have a manual reporting option though where you can report someone that you suspect of using a computer and they will manually review it. The manual review in my opinion is more reliable.

My experimental cheating experience on lichess

I personally have a dummy account that I have created for the sole purpose of experimenting on this, I was able to reach the 2400 rating mark in rapid (my maximum is 2000) and was still not banned (it has been active for a month!). 

Don’t worry, the account is permanently closed now. I am really just testing the boundaries of lichess’ anti-cheating detection system since I have been planning to write this article for a long time.

If you look at my current account you will say that I am only rated about 1800-1900 in faster time controls (I rarely play slow chess these days since I am so busy with this blog).

But this little experimentation of mine proves that you can get away with cheating in lichess and not get detected. 

I probably would have been caught eventually (because of the manual report option) but I did get away with it for a long time.

Moderators of lichess can detect cheating manually

A part of the cheating detection system in is a manual review of lichess moderators (real humans), they can look over accounts where the cheating is obvious and ban the user.

I have read this from a forum made by an actual verified lichess moderator, they actually do a manual review of the games.

This obviously has its limitations, any number of human reviewers would not be able to cover the thousands of games that are happening in lichess simultaneously. It would take a lot of manpower to accomplish such a task.

The manual reviewer can only usually ban users if the cheating is obvious and the anti-cheating detection system missed it for some reason.

False positives on lichess moderator’s manual review

The problem with the manual review of lichess moderators is if the cheating pattern is not so obvious, the moderator will have to design whether the ban should be implemented. 

And usually the ban is not going to be implemented since the users have to be given the benefit of the doubt, false positives are something that the moderators don’t want to deal with.

This doesn’t mean that false positives don’t occur though, it still happens on some occasions. This is why the manual review is not as reliable as you think, it is just a plus but is not the main thing.

User report is a part of the lichess anti-cheating system

Users can manually go to the profile of the user they are suspecting to have cheated, have the moderators review the account, and get the said player banned. 

Manual reports are also a part of the cheating detection system.

This is probably the biggest part of the lichess’ anti-cheating detection system, why spend all that money into automation where you can have hundreds of thousands of players to be the one who detects the cheating?

Users can go to the profile of the one that they suspect to be using a chess computer and report a manual review. The moderators will check the profile and determine if a ban is appropriate.

If someone actually does cheat on lichess eventually, someone will report them down the line when they gathered a high rating. 

High-rated players hates losing and will be keen on computer players, it is hard for a cheater to last without getting a manual report from their opponents.

Low chance of needing the anti-cheating system of lichess

I would say that if you are lower-rated (below 2000) there is a very low chance of you encountering a cheater and if you do, their cheating is going to be obvious that the automatic detection system of lichess can identify them. 

The problem begins when you’ve become higher rated. In lower-rated games your opponent is likely to not even know how to use the computer without getting detected.

They will definitely walk in the automatic anti-cheating detection system even if it is lousy. 

When you get higher rated though the computer players will also be harder to spot since they know what they are doing, they will dodge the system.

From my experience though you don’t have to worry about this, I almost never suspect my opponent to be using a computer since I can beat them most of the time (even if they are lower-rated).

It could occur, but just based on my experience it is more of a problem in higher-rated games than lower-rated games.

Obscurity on the anti-cheating detection system of lichess

The exact system that lichess is implementing is not exactly publicated, but it is clear that there are limitations in their cheating detection system.

In fact if you have searched anything about the lichess’ anti-detection system, you are unlikely to find anything else that is comprehensive besides this article (at the time of this writing).

The extent to which the anti-detection system is implemented is not described that well and is actually shrouded in secrecy for some reason. 

I have researched a lot of mini-information that lichess’ moderators have given but is not really comprehensive, maybe this can change in the future though.

I personally think that this is not good since such a huge organization such as lichess that a lot of people care about should value transparency among all else.

But as things stand that is the case, for now at least.

Funding of lichess and the subpar anti-cheating detection system

Lichess is a website funded by voluntary donations from its patrons, they are not a huge company with the financial backing that can implement a complicated cheating detection system like with is actually much better and open in their anti-cheating detection system which I believe is more reliable.

Lichess in general can be argued to be better than since it doesn’t blast you with advertisements that will attract you to spend money on the platform, but that is also its weakness.

Since it is not as commercialized as with, a more sophisticated anti-cheating detection system can not be in place. cannot allow their paying customers to be cheated on since a lot of people will complain. This is one of the advantages of, it is forced to make the platform much better since it is an official business.

Final thoughts

The lichess vs. debate keeps raging on, and I just can’t help but to insert such a topic in this article. When it comes to the anti-cheating detection system, I personally believe that lichess is quite sloppy. definitely has a better system for now (it may change in the future), but this doesn’t mean that is better than lichess indefinitely. There are many aspects that go into this.

I will have to repeat, you don’t have to worry about this since in my personal experience I rarely encounter cheaters in lichess, more often than not, the one you are playing is not really a cheater.

You should report when you think that it is necessary but don’t be too paranoid about this. I hope I have educated you through this article, sleep well and play chess.