Aristocracy/royalty that makes no sense, they actually need to do something for their subjects or you have nonstop peasant wars.
Succession laws exist for a good reason, just ask every kingdom that has gone through a civil war/succession crisis in history.
Religion is evil and corrupt, no exceptions.
Cities/castles are built like they exist in our world, instead of tackling the challenges of the setting. Magic and monsters would set a different paradigm of fortifications.
Overly long fights, especially when one side had a no-risk hidden power/trump and there wasn't a good reason not to use it already, except "plot demands it". If you can one punch the fight, your duty is to do it.
Forced Drama. Nuff said.
Things only happening "on screen". Time flows and events happen in-universe, even when we aren't observing. Especially annoying, when used in tandem with forced drama.
When you run out of ideas for romance, introduce a stalking horse/triangle from no where. Bonus points if one of the leads suddenly has huge baggage with them that wasn't hinted about at all.
Consistent consequences. If A died from it, then B should too, unless there is a good explanation for it.
Fake deaths when the character clearly should've died. Unless there is a good reason for it later, just kill 'em off.
Death/Dark/Gore for the sake of it. It doesn't make your work mature or high stakes or interesting, it just makes it edgy.
Redeeming characters, but them then never facing the consequences of their actions. Especially if they clearly should face legal punishment of some sort, but it's just brushed aside, because they now helped the MC.
Way too young protagonists doing stuff that they shouldn't be able to, even with special powers and eveyone is just okay with the elementary schooler doing all that. You can skip ahead and age them up, author.
Don't use power levels if you aren't going to keep it consistent.
