Hmm.. I hate the people who always brag about their role-playing abilities, ie; [i]Great grammar, spelling, depth, ext[/i]*

And when they finally post its something along the lines of;

"[b]they walks over to that Guy and nods.[/b]"

Nothing else. A simple sentence or something, and gives you almost nothing to work with. 

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Another thing is when your [i]really[/i] into a roleplay, and your getting out good length- detailed posts often and everything, and they just give you the most[i] worthless [/i]replies that take [i]forever[/i] and just make you want to cringe. I've had a[b] MILLION [/b]times where I have a good idea for a plot or something, and someone just ruins it and kills the fun or I have to carry the whole roleplay.