Bad gaming is worse than no gaming, and my late abusive ex made that blatantly clear to me, as she absolutely immersed herself in bad gaming.

* She thought that the DM's job was to try to kill the player characters
* She hated if there wasn't any violence for an hour or so

* her entire D&D setting could be mapped to Eco's 14 features of fascism
* For some reason her setting had to be better than all other settings. If I ran a game in a setting I created and there was a powerful mage, she insisted that mage be canonically weaker than her archmage

* Her archmage was a former PC of hers, as were many other powerful NPCs
* She'd get bored with any game that wasn't D&D set in her D&D setting. So bored that if she was running she'd have the aforementioned NPCs invade and wreck the place

* One time she decided that xenovirus Takis-A was too unrealistic so had a Wild Cards pandemic except everyone became cool aces and completely destroyed the setting she'd created just because of a crossover
* She'd routinely take credit for literally everything I created

* She'd change the rules on a dime and pretend they were always like that
* She was obsessed with house rules to make everything "more realistic" no matter the genre. Cyberpunk? Superheroes? High fantasy? Mage: The Ascension? MOAR REAL

* She hated games I liked and tore them down at every opportunity
* She'd deliberately set up situations to kill characters, but have a fit if one of her characters died.
* She'd do ridic things like "You didn't say your fighter took care of her longbow so the string snapped"

* If you came within a mile of applying this standard to her, she'd have a fit. It's a terrible standard, though but she didn't grasp why it was bad for her to do it to others
* She made sure to viciously trash every friend of mine she ever met once they were out of the house

* I remember setting up a fight in Shadowrun she could easily win and she accused me of setting it up to kill her character because she forgot enchanted weapons bypassed spirits' physical immunities

* One time she put a character of mine she built into a fight the character couldn't win. When I expressed frustration, she looked at the character she built for me and the character she minimaxed to attack mine, and then accused me of cheating because I had more total points.

* Sort of bringing several together: She'd change history whenever convenient to undo certain rulings, implement bad house rules, take credit for others' work, or disclaim credit for her own, and claim it was always this way.

Too many examples to really go into, but she was extremely pro-imperialism and pro-colonialism, and this would come up repeatedly. Loved to be told that the Irish couldn't be trusted to run Ireland and needed the British to set things right. This was because I'm Irish-American.

Forgot to mention when we got into Amber DRPG and she wanted to make her campaign setting the third (fourth) pole of reality, where it was the ultimate archetypal expression of magic, and no one in the multiverse could equal or exceed them.

Fourth because there were two patterns from the books

Oh lord I forgot the time she picked a fight with me over a Champions character I made who would resurrect with new powers every time she died. She insisted the character had to have a supernatural power source, that such a character was unfair to the GM because she couldn't kill

the character permanently, and that the character's super strength was unrealistic because she didn't look physically stronger than say Supergirl but could lift a tank.