So, I've seen over my past experience on lichess that a lot of people are wondering whether they should grant a takeback in a rated game.
To be honest, let me clear up an exception. In casual games, whoever wins or loses, doesn't matter at the end. Nobody loses or gains any rating points. So even if your opponent made a blunder that clearly wasn't a mouseslip in a casual game, and they ask for a takeback, you should still give them it. If they accidentally moved their king instead of castling, you can give them the takeback if you feel bad.
So, takebacks shouldn't be granted in a game. If your opponent made a mouseslip, so be it. I've had tilts start with a single mouseslip. First of all, many people have said that takebacks simply don't exist in real chess. And they're right. Whoever mouseslipped should've clicked more carefully.
This is an extremely short blog, but just to sum up, you should sometimes accept it if it's an obvious misclick so you can have a good game. Not always, but sometimes. And if you want to, you should, and if you don't want to, you shouldn't.
