Too sober to deal with this shit.

Rather, what makes a bad roleplayer? There are many different things that constitute to a roleplay, and any number of them can be bad to combine in many different ways and create what is a bad roleplayer. But first let me explain some of these.

1. Illiteracy. I do not mean script role playing, by any means. Of my most enjoyable roleplays, many have been script. What I mean is when someone is simply… Illiterate. When they can’t spell many of the words they choose to use, when they fudge up their grammar a lot… this contributes to many bad roleplayers’ reputations. It is understandable if they’re not a native English speaker, of course, and there are some good roleplayers who don’t use the best English, but most who are really bad with it tend to be rather substandard.

2. Characterization. Do they roleplay the specific character well? This is basically the definition of a roleplayer, here, whether they do this or not. Bad roleplayers will typically not respond appropriately for their character, and the most egregious examples of this come from when they make the character act this way just for their ships. For example, when Eridan is made into a sad woobie who needs love and attention. Or when a Vriska goes and starts getting all blushuu over a Tavros. It could, however, be considered appropriate if the two characters in roleplay have had a developing relationship, or the roleplayers have agreed to this; if a random roleplayer comes up to you and tries to be kawaii desu and all that on your character put of nowhere, however, that is typically a bad roleplayer.
As well, people who do not understand their characters’ typing quirks are usually mediocre. For example, Eridans who use fish puns with anyone but Feferi, or Feferis who put dashes before lowercase e or any capital letter. Not to be nitpicky, but if you like the character so much you have a desire to roleplay them, you should study their quirk. Equius doesn’t use punctuation. Vriska types perfect English save for her eights. Terezi doesn’t use periods unless she is using an ellipse. I don’t even roleplay any of these characters and I know this.
As such, a way to avoid bad characterization is to read through your character’s pesterlogs beforehand! You may find something interesting, such as the only times Tavros used an ellipse was when Gamzee had offered making out and when he was trying to flirt with Jade.
Also, for the love of all that is holy, please, please, PLEASE do not say gog or jegus unless you are Terezi or Dave. (Vriska does say gog once, so that is okay, I suppose, as long as it is used sparingly.) Trolls do say god. Sollux says, “oh my god.” when Karkat’s computer explodes. As well, Tavros says, “oH MY GOD,” when Vriska tells him to go try out all the stairs in the lab.
On a final note for this, please, do not assume that everyone agrees on the same fanon. Particularly when it defies canon.

3. Style of roleplaying. This has mostly been covered in the first two points, but, there is something that must be put here, separate from them. Two things, as a matter of fact.
One. Godmodding. This can range from becoming invincible to determining what the character you are roleplaying with will do and acting as if they did so in your post. It frustrates people, and makes you look bad.
Two. Entering another person’s roleplay without asking permission. I myself am usually hesitant to roleplay with more than two people at a time. However, one day I made a wall post. Everything was going smoothly in the roleplay until I had went to bed to continue in the morning. When I awoke, I saw that someone else had hijacked my roleplay and acted as if my character wasn’t even there anymore, and finished it up for me. Even when the roleplayers are still there, it can be considered very rude unless you know them well. As well, when you enter a roleplay, have a good reason for your character being there (if it’s lit); don’t just be like BREAKS THROUGH A WINDOW.

Someone can meet any one of these requirements and still be a good roleplayer, but more often than not they aren’t very great. There may be others, as well, but it seems these are the major problems.

-♉