> You ought not to endeavour to amuse and deceive your adversary, by pretending to have made bad moves, and saying you have now lost the game, in order to make him secure and careless, and inattentive to your schemes; for this is fraud, and deceit, not skill in the game.

I tend to see rated chess as a battle and therefore all is fair in love and chess.

> You ought not to endeavour to amuse and deceive your adversary, by pretending to have made bad moves, and saying you have now lost the game

I've done a variation of this in a rated game. Like pretend I accidentally touched a piece and now am compelled to move it. Loud sigh. It was effective at least once, both of us patzers. It hadn't occurred to me that I should feel bad about it. I'm not sure I do.