Consent and fair play can both provide reasonable justifications for the deceptive behavior in some contexts. If you agree to play poker with me, you can’t complain if I bluff — though you certainly could complain if you caught me playing with a marked deck. But these reasons do not necessarily work in the case of all adversarial institutions.
To an extent, part of what adversaries do is deceive and coerce people in order to win the game that they are a part of. This deception amongst adversaries is part of the game, not accidental. The minute difference between a foul and an intentional foul in the sport of boxing is just one example. In order to win, some boxers try to disguise intentional fouls as mere accidents. In his book Ethics for Adversaries, Applbaum argues that those within adversarial institutions have a better chance of getting away with actions that might not be as acceptable in other situations.
“One cannot coherently claim that one aims at the good ends of a competitive system if one seeks to undermine features of the system that make it good. Perhaps the claims that adversaries make about their aims and the actions that they take cannot be made to cohere. Or perhaps the good ends of the system are for its practitioners a sort of idle hope that is unconnected to what their actions aim at. But there is no plausible way to redescribe the violation that adversaries aim at as accidental, a foreseen but unintended side effect. If, to pass a test of reasonable acceptance, actions cannot aim at violation, then much of the violation that results from adversary institutions does not pass the test” – Applbaum, p. 187
When one plays to win, it can often involve actions that undermine the aims of the game. If adversaries are aiming at good ends, then the violations they inflict upon one another can be reasonably justified. As the final sentence of the quote implies, however, not all violations of normal moral codes (like honesty) in adversarial institutions are accidental.
In short, for Applbaum, the good ends of deliberately adversarial institutions will not always justify the means if the means are deliberately unethical.