Hey, evil isnt ALL bad...
If you've played any amount of TTRPGs, you've come across some variation of this quote (or on the other side of the screen, you may have *said* it)
"I would never allow an evil player character in my campaign ."
Yes?
We've all heard it?
Well I'm here to maybe make you think about this!
Allow me to preface this with: your campaign is your campaign, if you don't want an evil player character- that's fine. You do you, I will do me, and we will all have fun at our respective tables and it's great. Ok? Ok.
So. What is an evil character?
Broken down to a very brief statement, 5e D&D states:
Lawful Evil- puts themselves first, follows a code.
Neutral Evil- does what they can get away with without compassion or regret .
Chaotic Evil- Arbitrary acts out of greed and hate.
So, there it is. Plain as day. Those are the cores of an evil character.
So let's start with how this is problematic.
A player might see this as free reign to do as they please. It's time to kill townspeople, start fires, eat guards, and derail campaigns with the other oft spoken phrase being barfed out:
"Its what my character would do!"
But...if you think about it? it really *isn't*.
Because, really its important to remember one thing about someone who is evil. They arent stupid. They're always thinking about how to fulfill their *need*. So therefore... EVIL WOULDN'T ADVERTISE ITSELF/DRAW ATTENTION TO ITSELF. Things just dont get done that way, and theres very little that can be done when you're constantly behind bars or hounded by the local constabulary. If you're just blatantly doing things without plan, or foresight, or thought you aren't being evil, you're just being an asshole.
The only one on the evil alignment who acts at random is chaotic evil, and even then it's out of greed and hatred- which aren't constant feelings, even in a evil character.
So thinking about this then, the problem isnt with evil characters... the problem is with the players.
So.. then why have evil PCs?
First, it makes for interesting group dynamics. Second, you (as the DM) potentially have an available tool to utilize as a secret spy, or hindrance to the party. Third and most importantly it also leads to amazing RP and stories.
If a player indicates to you that they want to be evil, instead of immediately shutting them down, sit with them and go over these questions:
1. What is the evil character's motivation?
(Revenge? Preventing a greater evil from disrupting their lives? Looking out for someone? Seeking power?...)
2. Why are they willing to help the good/neutral guys to begin with?
(Are they related to one? Do they owe a favor? Are they biding their time? Hiding in plain sight? Strength in numbers? A means to an end?...)
3. How did they become evil?
(Are they just greedy? Is their profession [say, assassin, thief, etc] just that way?, were they cursed? Is the source of their power evil/corrupting them?)
4. What is their ultimate goal?
(This can tie back to question 1, but it can also lead to a potential redemption arc, or a ultimate betrayal/deception.)
If the player does things right, the rest of the group should never suspect there is evil in their midst. When/if it is eventually realized, it should be impactful... it should mean something.
Stories are built... friendships are forged... secrets are harbored... all because a evil character was allowed to play.
Think about it.