Gaslighting is an overused phrase in modern social media parlance largely because it is actually the most successful form of getting away with it and has been for years.
The first of lesson in gaslighting is that it's never your fault. Especially if you are a man. Great examples of the ancient form, she's a witch who some how used her magic spells to make you want to have sex with her. Temptress, harlot, progressing neatly to the modern day golddigger or perhaps, if she hadn't worn that short skirt and flashed her eyes like that, you would never have noticed her. Her constant complaining made you want to have an affair. .
Second lesson of gaslighting is do not under any circumstances admit guilt. This is actually the hardest part. The whole point of gaslighting is exposing the weakness in other people. The worst think you can therefore do is let your own weakness come to the fore. Denial even in the face of absolute truth is very powerful. Because your accuser has to accuse you of lying or question her own evidence. The accusation of lying against a partner is almost the nuclear option. Partners are less likely to throw a bomb into a relationship because the consequence of such a truth is that the relationship has to end. By denying this truth, the accuser has to work backwards to explain away evidence. The self-doubt generated is extraordinary. Done once, a crack is opened in the door, it's easy to force the window wider and gaslighting is in full swing. Examples of this including, you being seen kissing a girl only to be explained as a quick peck on the cheek with a friend, persuading the accuser that they didn't see the kiss at all.
The third lesson is deflection. If the rules of blame and denial are failing, it's now better to create a diversion. Classic in this genre is to declare illness. Your partner will immediately be obliged to show sympathy and if they area already semi-gaslighted they will be happy to accept the excuse not to face the truth. The gaslit partner is the most caring ever. The other form of deflection is that common in the legal form. Blame the process, make them question procedure because whilst all your accusers are discussing which is the correct process, the rules of the game, you're still getting away with it.
It's an artform and can be taken to any extreme. Practice is the key. Once you experience and see how powerful it is to reduce your accuser to doubting their own self-worth, the game is won. Once you see it, it can't be unseen. it's everywhere in life, in the workplace, in politics, especially in the government.
Government are the masters of gaslighting, persuading a nation that the countries problems they created are somehow the fault of foreigners, bureaucracy, looney left councils, single mothers or anyone who gives a shit.
Practice makes perfect. The gaslighter has nothing to fear from the truth because the truth is whatever you say it is.