Because chess is life, and there is no undo button in life.
Why is there not an option to undo your moves?


cuz there are even bad people who may misuse this privilege and undo the blunders they made not accidentally

Sometimes, most of the players here, including me, accidentally do wrong moves; either the mouse or the finger (touch screen) slips, or anything like that and there's no option to undo the move. In this case we should be able to undo our moves; but some players might abuse it, so we should put a limit to this too; let's say we can only undo a maximum of 3 or 5 moves in one game. Many of us lost a lot of score just because of that, for example; falling from ~1300 to ~1100.
This is a suggestion
Take back is available in unrated Daily play only and had to be configured in the challenge.

To play a game where takebacks are allowed , before game starts do the following :
Choose Unrated rather than rated
Switch on Allow takebacks
Takebacks are not allowed in rated games.
Chess is about touch move. I can elaborate more on the issue, but there is no need. Also some people gets mad when you take time to think, also here I will not elaborate. Chess is about thinking and touch move. There will be mistakes in moving not related to thinking, well .... good luck

but learning to “touch move” and not moving/canceling every candidate move to see what looks best
try to do it all visually and then move when ready
i think it helps in the long run

It's not that difficult to not mouse-slip. And if you do, it's not like you're playing for the World Championship. You just lose, if it's a really bad mouse slip, and then go on to the next game! If you mouse slip regularly then there's something wrong with how you are playing that you need to look at fixing.

Because chess is life, and there is no undo button in life.
It is just a game and games have rules.

Because chess is life, and there is no undo button in life.
It is just a game and games have rules.
The rules don't include taking moves back though.
cuz there are even bad people who may misuse this privilege and undo the blunders they made not accidentally
--- That is Very True !

that L-chess site has "takebacks" that your opponent might accept. Maybe a premium-only option or something here? just an idea....
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Enter the platform on YOUTBE and write the name of the song and the name of the Band
Rock Glitter The Heavy Rock Band
https://youtu.be/_cSCi0p8a70 (un Atleta con playera azul que dice usa)
https://www.youtube.com/watch?v=_cSCi0p8a70&feature=youtu.be
Tu Ausencia The Heavy Rock Band
https://youtu.be/UMHP3KFCk_o (una luna en la noche)
https://www.youtube.com/watch?v=UMHP3KFCk_o&feature=youtu.be
Fue Ayer The Heavy Rock Band
https://www.youtube.com/watch?v=QrAe09nHB5Y
https://youtu.be/QrAe09nHB5Y (un torito café)
Sometimes, most of the players here, including me, accidentally do wrong moves; either the mouse or the finger (touch screen) slips, or anything like that and there's no option to undo the move. In this case we should be able to undo our moves; but some players might abuse it, so we should put a limit to this too; let's say we can only undo a maximum of 3 or 5 moves in one game. Many of us lost a lot of score just because of that, for example; falling from ~1300 to ~1100.
This is a suggestion