When I was in highschool, me and my friends would roleplay. But it'd always seem to devolve into a word count post match. No matter how it actually added to the current story, it would be hundreds upon hundreds of words explaining how they killed a few wolves. The kind of detail that honestly gets boring to read after a while. (at least for me.)

My pet peeves from my experiences of role playing. God modding in any manner. Building overpowered characters is so commonplace, it's a challenge to balance perfectly but often most people don't try very hard. Though not just that, if you're in a roleplay that involves action, expect your character to be in danger, they can get hurt, they can die. (usually you let people make another character.) Basically, assuming your character is immortal, and people that quit or get upset because they die. There's a lot more that fits into that category. But that's my short explanation.

Another one...Quitters, without reasonable explanations. It's a real bummer when you get people into an RP and they post one or twice and you never see them again.