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All About Cheating: Questions and Answers

Asked by Chess_Agent
Tags cheating engine marked sandbagging boosting ban computer correspondence artificially faq
Activity Viewed 92155 times, last updated
All about cheating... If you have a question about cheating that wasn't addressed in this answer, feel free to leave a comment and this answer will be updated with your question its answer.

1. What is cheating? What is boosting? What is sandbagging?
2. Can I use an engine in casual games (or against stockfish/the puzzles/opening training)?
3. Is it cheating if I use an opening book for correspondence games?
4. How are cheaters identified?
5. I think my opponent (or any registered member) cheated. What do I do?
6. Can I get my rating points back if I played against a cheater?
7. I was marked as a cheater/sandbagger/booster even though I didn't cheat. What do I do?
8. Can cheaters play in tournaments?
9. If someone's caught cheating during a tournament, what happens?
10. I'm going to create a new account because I've been marked. Why shouldn't I?
11. Someone keeps accusing me of cheating. I didn't cheat... What do I do?
12. Is it cheating when people abandon their games and/or when they let their time run out?
13. If someone else uses my account to play, is that cheating?
BeL0ve commented :
Why, during a tournament, do players often withdraw for a period of time then re-join moments later? Is this done in order to pair themselves with lower rated players so that they have a better chance of winning and thus gain more points during the tournament? If so, is this 'stacking the deck' considered cheating, or an acceptable part of tournament strategy? Thanks.
seanysean commented :
No, that is not considered cheating Bel0ve.
SpinRightRound commented :
How do I know if I've been marked? (I'm pretty much sure I shouldn't have been flagged, but according to "This flag will be visible in public to everybody except the cheater" it's not possible to really know)
EagleOnHigh commented :
I was just notified that I "lost to a cheater", and I was refunded 14 rating points. That's great! I was wondering how I might figure out which game it was where I played the cheater. I am also curious now about how often lichess scans games for cheating. I'm not good at picking up on this stuff -- I am kind of oblivious to cheating, though sometimes I notice my opponent makes very few mistakes. Thanks!
Bellinzonachess commented :
Hello, I Play here thousand of blitz games (3'+2"). Sometime a lose a lot of games in few days, sometime I win a lot of games. It happens to me maybe 3 times that someone wrote me: "You are a cheater". I've never use a Computer. But I'm chess Player, probably after some lost I've analized them with a Computer, so next time I see the same Position, maybe I can remember the same Position and same tactical trick and will win very quick. But this can't be considered as a cheater. Or maybe my Opponent made a slip mouse move: If I don't accept to repeat the move, according to FIDE rules this is NOT unfair! Please everyone can't invent some new rules like "Oh I did a mistake, now I pretent to repeat the move". Come on: please read the FIDE rules.
Bellinzonachess commented :
And how can you say: he is a cheater ? Is impossible. Maybe my opponent just plays good moves. It happens sometimes. The rule "if your opponent does no mistakes, he is a cheater" really really suprise me. I don't accept it is ridicoulus! Claudio Cucchiani (CH Elo 1997, FIDE Elo about 2000, having beaten some Elo 2200 in my career and never had an unfair problem during a games after 30 years.).
18 Answers
Answered by Chess_Agent
1. What is cheating? What is boosting? What is sandbagging?

A: In the context of the rules on Lichess, the general definition of "cheating" is when players use means other than their own chess intellect to win rated games or otherwise boost their ratings. Examples of cheating include:

- Using a computer player (or chess engine) to play the game;
- Lending access to a game to another individual for help with moves;
- Creating additional Lichess accounts to boost (boosting) or lower (sandbagging) one's rating*;

Boosting and sandbagging are both forms of cheating. More information about these two can be accessed here:

A cheater's profile will have a header saying, "This player uses chess computer assistance" (or This player artificially increases/decreases their rating). This flag will be visible in public to everybody except the cheater.

2. Can I use an engine in casual games (or against stockfish/the puzzles/opening training)?

A: Yes. You may ONLY IF YOUR OPPONENT KNOWS AND YOU HAVE THEIR EXPLICIT PERMISSION TO DO SO. If someone wants to play a computer, they can play vs. AI. They should have expectation that they're playing a human if they accept a human's challenge. You can use an engine against the lichess built-in AI ("play with the machine" on homepage) if you please; games against the computer are never rated. Similarly, using an engine to solve a puzzle (or help you in the opening training) is not against the rules and you will not be marked as a cheater. But, should you use an engine for the training puzzles/openings, you'll only be cheating yourself.

3. Is it cheating if I use an opening book for correspondence games?

A: You may use an *opening book* or *games database* for rated and unrated CORRESPONDENCE games. You can use a *book* and not an engine.

4. How are cheaters identified?

- Using the suspicious games themselves. The degree to which computer players differ in playing style and strength, to most human opponents that rely on them, is in most cases enough to reverse-engineer information from the game beyond what moves were made.
- Using the player's other games. A player's profile shows all their games, including games where it is apparent that there was no cheating. Games where a player cheated and games where a player did not cheat have very different results when reviewing them using a chess engine (or Lichess' computer analysis feature).
- Using the player's history. On every player's profile are public graphs of rating and average history, game database exports upon request, and win to loss ratio.
- Time statistics. Anyone can see the public time consummation information for games, i.e., the time-per-moves.
- A statistical analysis of the suspected user's playing behaviour. This statistical analysis is only visible to the lichess team.
- Copying and pasting the suspicious game(s) into an engine and seeing how similar the moves are.

5. I think my opponent (or any registered member) cheated. What do I do?

A: First, please request a computer analysis and check yourself: if your opponent had 7 blunders, 3 mistakes and 27 inaccuracies, it's very unlikely s/he cheated. However, if your opponent has 0 blunders, 0 mistakes, 0 inaccuracies and a very low centipawn loss, it's more probable that your opponent cheated.

If, after viewing the game analysis, you still think your opponent has cheated, please submit a report against the user. You can report them by clicking their name and clicking the report button on their profile. Alternatively, you can use the report form: ... Please do NOT post about it in the forum; your post will be deleted.

If you think an anonymous player cheated, please don't send us the game. Anonymous players can't play rated games. Also, we can't identify anonymous players and consequently can't do anything about it.

6. Can I get my rating points back if I played against a cheater?

A: Yes, there are rating refunds. For the rules about when you are eligible for a rating refund, see this post:

7. I was marked as a cheater/sandbagger/booster even though I didn't cheat. What do I do?

A: It is possible, though not very likely, that you were incorrectly flagged as a cheater. You can email lichess at arguing your case. As in real life, ignorance isn't an excuse for being marked. Again, please don't plead your innocence in the forums.

8. Can cheaters play in tournaments?

A: Nope.

9. If someone's caught cheating during a tournament, what happens?

A: They get expelled from the tournament.

10. I'm going to create a new account because I've been marked. Why shouldn't I?

A: You shouldn't create a new account because you marked. You're only allowed one account. If you believe you've been incorrectly marked, refer to point 7. If you really need more than one account, and you're going to use it for legitimate purposes, just ask. You can email with your situation.

11. Someone keeps accusing me of cheating. I didn't cheat... What do I do?

A: Don't worry about it. If you aren't cheating, continue as you were; nothing will happen.

If someone starts accusing you (or being annoying), just click the little tick in the chat box so you can't see what they're saying. If they seriously think you're cheating, they'll report you. You can, additionally, report them as a troll.

12. Is it cheating when people abandon their games and/or when they let their time run out?

A: If your opponent frequently aborts and/or leaves games (without resigning/drawing/winning/losing) then lichess' "playban" system will temporarly ban them from playing games for a set amount of time. The more someone leaves/aborts, the longer the ban is.

If your opponent lets their clock run down for whatever reason - usually because they're losing, the mods can't do anything about that. It's bad sport not cheating. See this link for more information:

However, if it's consistent (i.e.: they join games for the purpose of letting their time run out), that could be considered artificially decreasing the rating.

13. If someone else uses my account to play, is that cheating?

A: It is not permitted to give anyone access to your account. If you do, and they play rated games, then yes: that is cheating. If they play casual games then, no, that's not cheating.

If they play rated games on your account, it's cheating because it's someone else gaining/losing rating points on someone else's account.

More information on this matter here:

* If you have a question about cheating, please add a comment below and this answer will be updated with your question and your answer.
Solal35 commented :
What is the advantage of sandbagging cheaters ?
Chess_Agent commented :
Solal35: Since sandbagging is a form of cheating, sandbaggers are awarded with a nice red label. Also so they don't sandbag more -> they can't play rated games.
tisnjh commented :
On a normal game, when they lose, they usually lose very few rating points. However, they can suddenly purposely win against a person they hate. Since their rating is so low, the person they play against will lose lots of rating points.
Solal35 commented :
Ok thanks for your answer !
Dolg commented :
to 9.
Once thibalt said it is OK having multiple account if it is for a good reason. I also have 3 accounts, one for blindfolded chess and one where I test thing (for example new openings).
IvanRajic commented :
I beat an opponent, so that he had one only one move to play, after which I would have checkmated him in his next move. He did not leave the game, did not play his last move, and did not resign. That leaves me with an option of either resigning myself or waiting it out. If there's a lot of time left, that can be inconvenient.

Does this count as cheating, and what can I do about it, apart from reporting it?
Chess_Agent commented :
No, it's not cheating.

It's terrible sport on your opponent's part but since both of you agreed to the time constraints/conditions.

I suppose you could wait it out by doing something else (but keep the sound on so you know if he moves!). Even if you do report it, mods can't do anything against that because, well, you both agreed to the game.
ProgramFOX commented :
About "8. Can cheaters play in tournaments? Nope.", I'm not sure; I've seen boosters play in rated tournaments (when they were already marked as booster), but the games they played weren't rated.
Unihedron commented :
ProgramFOX: I've recorded a gfy showing how cheaters cannot join tournaments after being marked: However, I don't think there's a mechanism for booting cheaters from tournaments if they were already playing when the tournament was running.
ProgramFOX commented :
@Unihedron: In the tournament winner was a booster, and was already marked as booster when he joined.
chesseric commented :
On a rematch I played my first move as white. My opponent did not move and his clock did not start. I left the game. Later I found he played his first move and won the game on time. Shouldn't black's clock start after white plays his first move?
Chess_Agent commented :
You did play your first move. You said so yourself. The clock actually starts once black moves.

If your opponent doesn't move, wait 15 seconds and then abort the game (that way you won't get penalized by the playban system).
chesseric commented :
Is there an abort button available while waiting for black to make their first move? I didn't see one and thought my only option was to leave the game?
Chess_Agent commented :
Yup, there'a always an abort button for the first move (white and black). After black moves, you are unable to abort your game. It's the big X next to the draw and resign buttons.
mordedor commented :
So, why not lock de analytics(computer) cheat, while a playing match or lock session???

Players, include me, using this in a game and its a sure victory.
cat_person commented :
What about opening books for rated correspondence games? This is considered cheating in ToS but not here...I did that in the past exactly because of this answer...and told each new opponent this fact as courtesy as instructed here...until people told me the existence of ToS after which I played no more (new) games with opening books. This is confusing so would you please clarify? Thank you very much!
Psretired commented :
Somehow the opponent got the app to not show his move, have his clock tick to zero, yet have me reported as leaving game and losing when his clock ran out. I am able to chat, refresh browser and show a connection and have 8 minutes on my clock. I should not be reported as leaving the game with window open and chat ability still functioning and app running. How can I have left the game with 8 minutes on clock?
Chess_Agent commented :
It's probably a network error on your end.
Teddy-Broosevelt commented :
I guess i was flagged as a cheater and just found out. I looked around and saw that someone had been getting onto my account and found out it was my brother and he said that there was a way to cheat. Is there any way I can get my account unflagged.
Chess_Agent commented :
7. I was marked as a cheater/sandbagger/booster even though I didn't cheat. What do I do?

A: It is possible, though not very likely, that you were incorrectly flagged as a cheater. You can email lichess at arguing your case. Or, you can report yourself and argue your case. As in real life, ignorance isn't an excuse for being marked. Again, please don't plead your innocence in the forums.
umeshnaithani commented :
if someone cheats . there is any real punishment except red flag and permanently banned. for example jail. :)
ilidiomartins commented :
About this answer:

3. Is it cheating if I use an opening book for correspondence games?

And about other time control?? Classical, blitz ... Is this consider cheating

Refering to:
Chess_Agent commented :
You can only use an opening book in a correspondence game.
Onein144kKings commented :
What about using the analysis board during a correspondence game? Is that considered cheating? I mean, I would assume that if you provide such a button during a game, it isn't, but I don't want to risk getting flagged, although I suspect I'm playing with a handicap by not using that since everybody else in correspondence uses it probably.
Chess_Agent commented :
Analysis board is there for you to use. Go crazy!
kaynight commented :
this is a very helpful q+a than queue, is it sandbagging to play better one day than the next
Chess_Agent commented :
Thanks! Nope, unless it's deliberate.
ascer commented :
You might been banned from lobby games within 15 minutes.
olejorgenb commented :
Eh, the opening explorer in the analysis board of correspondence games should really be disabled then?

I think lichess remember whether it's open, so if you've analyzed a finished game and then use the analysis board in correspondence the opening explorer will be open.

If it's considered cheating it shouldn't be available at alll - at least without a warning when it's opened.
DvdAvins commented :
When you say opening *books* are allowed for correspondence play, do you mean only physical, paper book? Or is use of a game database (with absolutely no engine) permitted?
muheym commented :
so if your average centipawn very low you are a cheater?
Horson commented :
How long takes lichess to check reported cheater ?
lessi2015 commented :
is it too hard for me to write on a tablet
Sxakamanto commented :
I think you should think things over when accusing someone of sandbagging!!
In my case most of my victories or losses depend on my connection. So, I may win against a high rated player or lose to a low rated one. Anyway, I don't care, I just play chess for fun!!
jez9999 commented :
It seems very harsh to give a lifetime punishment on the site for cheating once. It also rather encourages the creation of new accounts. What I would do is mark the account as cheating for maybe a few months, or have a 3 strikes and you're out system.
Areonpanaligann commented :
Plsss . Closed close the account (Credo_the_magician) he is using an Engine .. Pls look at our games

Stephenson commented :
I'm getting a good laugh. Reading comments from two years ago until today.
Aksoan commented :
Impressed by the anticheat systems. Seems LiChess is so fair.
Just one question- if a player keeps switching engine levels so sometimes he makes a bad move and at other times a perfect move how would LiChess catch that cheater? I cannot confirm this but I think my friend does this (he said it but he could be lying).
realpawn commented :
do you approve this?
redhorse989 commented :
What is a sandbagger ?
Shiaxou commented :
A sandbagger is someone who intentionally loses rating points in order to more often get matched against lower rated opponents. This is considered cheating mostly because the player's skill level is higher than their rating shows, thus creating an unfair game.
Answered by gregmoore ......A youtube video where at 17:43 into the video Lichess founder Thibault Duplessis talks about cheating
Es-tactic commented :
Why did you start the video at t=704 when the cheating part starts at t=1063
Answered by javacertified
I see an account has been closed. How can I tell if they were identified as a cheater?
Toadofsky commented :
You cannot .
Answered by SB6
If you cheat and lichess stops changing your score, is that permanent?
Musicknight123 commented :
No, its
Answered by LiquidEggProduct
I recently was paired against an opponent, I was White, opponent was Black. The opponent aborted, then challenged me.

I accepted, and the colors were reversed. Looking to the player's history, he does this very frequently, almost always aborting with Black, and gladly playing with White.

This isn't exactly cheating (I won easily, clearly not computer-assisted), but seems to be against the spirit of fair play. Would this player's account be reviewed? (Perfectly understandable if lichess needs to focus resources more on other scenarios)
Chess_Agent commented :
S/he probably just has a strong preference for playing only one color. That's not cheating. As long as they don't abort like that in tournaments, it's okay.
LiquidEggProduct commented :
Yes, personally it's not a big deal. Others might not appreciate it. If White didn't have an advantage over Black, probably no one would care at all.
metterklume commented :
It's not cheating but I've encountered opponents who do this and it certainly is annoying. I wish the server could send them an automatic message asking them to use the create game feature with choice of colour. I suspect some of them just don't know.
odjegba commented :
doesnt even make sense
Toadofsky commented :
Use the report form .
InnateAluminum commented :
They'll have a lower Game Completion rate, if they abort every time it should be around 50% in the long run. So play with opponents with 100% Game Completion rate.
Answered by ayushmanvats
What if i reported a player without any reason?
Answered by ChessQueen33
I played a game and my computer crashed or something but I couldn't move.
My time was very low, just a few seconds, and because I didn't move I lost because my time was up. Next, I got a message 'Watch out, ChessQueen33. Letting time run out instead of resigning can result in a temporary ban' or something. But how much can this be repeated before I got banned? I don't want to get banned and I didn't do anything!
The game link is:
Answered by Slava_Dzu
I apologize for not being able to write there, but please draw the moderators to this player and watch the games with him. maybe I'm wrong....

Hello, it seems to me that here is the "sitasree" player Cheater, but I can be wrong. after I told him that he said he gave up. Check it or him look or see behind it or him .... Simply at such level not really so to go or he groysmejster which was registered))))

Toadofsky commented :
Use the report form .
Answered by Farcical
What if you have been accused for cheating and marked, then banned. AND you did not cheat, most everyone you contact agrees with you, you have sent out an email and received no response, then proceeded to post on the forum, then proceeded to create a new account.
I want to play, and I feel that I should not be hindered due to some individual person's mistake. If someone at lichess disagrees that I should be able to play here after committing no wrong, let it be known so that I can pursue appropriate action exterior to an internal and informal correction.
Just for the necessary record. This is my third attempt to contact lichess as an appreciative member. As of now I have no intention to pursue any further action; for the greater interest of us all, let's keep it that way.
futbol commented :
I'm in the same situation. I was incorrectly accused as cheating. I feel like it is not a just process to ban someones account without notifying them of what they were banned for as I have no clue why my account was marked. My profile says I've used computer assistance; however I'd love to see the game where I was called out for cheating because I'll take that as big compliment that I'm playing chess at an engine level! I'll re-post an update if lichess ever decides to get back to me and do the right thing.
Answered by Kvisko067
please check the max0811 user, i think i use a computer, i think That he is cheater
Toadofsky commented :
Use the report form .
Answered by hk2018
hi , my page diconnects meny time from receiver of and this is always result of my banning . what can i do?
Answered by Tisernhagen
That is not cheating, that is bad sportsmanship and lying.
Answered by hardtech
hello , I got banned for nothing . My brother was helping me how to play it the chess . I was not cheating
Answered by Hrach49
Hello I was banned for nothing. Please unban me I have just played with one guy with no knowledge of chess he lost me and like a idiot he reported me with no proof
SneakyBishop commented :
Somehow I doubt they would ban you without sufficient evidence.
Answered by SneakyBishop
If I understand your answer to question 4, you use legit gameplay as a baseline to detect likely cheating behavior.

Do you use AI to detect any of those differences?

Sorry if this is an ignorant question - I am not a coder.
Answered by sokoff
hello, user sokoff, what am I cheating? remove the black label
GaleyiVerGaleyi commented :
is it writing in my profile like (this player uses a chess programme?)
Answered by yiddishforkiddush
I reported a cheater and it's been over 24 yrs, how long does it take to flag someone as a cheater?
Chess_Agent commented :
Reporting someone for cheating doesn't mean they will be flagged. But your report was received and was added to the list of reports to be reviewed.
NM Wayzata-TitusA commented :
Wait, lichess has existed for 24 years? That's amazing considering the internet is just a few years older :)
Answered by LadyNorth
Not sure if this is the correct place to post this, but I just started a game, the phone rang and when I came back I apologized to the player and asked him to give me time back because I had to go answer the phone, he said ok but he never gave me any time back, he just let the time run out to win. Is this considered a form of cheating? Here is the link to that match [Link Deleted]

Chess_Agent commented :
If leaving his time to run out was a habit, that would be sandbagging and he'd be flagged. It doesn't seem like it's done often though, so he's good.

LadyNorth commented :
I think you misunderstood my question but it's ok I found out that he was just being a "bad sport". But I'm confused by your answer because according to what it says above about sandbagging, sandbagging is artificially increasing/decreasing one's rating in order to win. Also it states that letting one's time run out is considered "bad sport" and not a form of cheating, so did I misread what it says about these 2 situations? I just want to be clear because I do let my time run out quite often sadly due to the fact that there appears to be a lot of people sandbagging and they are not hard to spot when I play against them, yet to prove that they have artificially decreased their rating in order to win against lower rated players like me is hard, so I usually let my time run out as a form of punishment. Sorry I'm a woman and I tend to ramble on, hope i didn't confuse you with my long reply here.
Chess_Agent commented :
I updated the answer. Basically, if it's too consistent (join games for the purpose of letting time run out), it could be called sandbagging because they are manipulating their rating. The mods will use their discretion in this case. Hope this helps.
Jorge_Laveaga commented :
Hi, im a cheater.
What happens if Im playing blitz and when I move black just doesnt move at all. If i leave the game, what happens?
coolkidjuju commented :
GOD people have SOOOO many comments o o
arumakan90 commented :
hello. player "Zira" use chess programm, you can see in 2 last games with me. first game he play normal, but next game he play with programm, he go out every he need move and he's moves be a very strong, but first game he play very weak. sorry for my bad english.thank you.
I keep being paired with an opponent I do not want to play over and over. ( I suspect computer aide) I cannot abort without a warning. I cannot refuse to play the first move without a warning. isn't there a way to block the pairing in the first place?
yelaw commented :
yes there is
google it
gio52 commented :
My opponent in a 5 minutes blitz game was able to play 15-20 moves in 1-2 secs is it possible legally ?
aattila78 commented :
Check his ultrabullet rating, is possible
sazzadul100 commented :
can i use engine against leelachess in casual games?/

Only registered members with one week of lichess activity can contribute to the Q&A.