I want to run a good alignment campaign in D&D 5e with my friends, but we are not even at session 0 and we already have a major disagreement.
I usually GM tabletop RPGs that are not D&D, like World of Darkness, Call of Cthulhu, AFMBE, LORT 6D, Star Wars 6D but occasionally I DM Pathfinder and D&D oneshots. I'm experienced as GM but I'm still quite new to the D&D world.
Recently a guy new to the group decided that he wanted to DM D&D after I made a oneshot in 5e. It's been quite fun despite a disagreement in how we see alignments. We are playing a "good" campaign but in his world some PC races are evil period like Tieflings or Half-Orcs and some of the PCs in the party are of one of those two races, he argues that there is no such thing as evil and that being evil is just a point of view. This caused some trouble with my LG life cleric but since I'm the only one in the entire group that sees it that way I decided to come to an agreement and commit to it; after all, I don't want to kill the fun.
So far so good, the DM and I had a disagreement, talked about it and found a solution. But there is where my problems start when I decided to start my own homebrew 5e campaign with my tabletop friends. I decided to make the usual good vs evil campaign, but some of the players that also play in my friend's game want to play evil characters. When I told them that in "D&D the good and evil is black and white there are no greys" they use the same argument as the other DM there is no such thing as evil it's only the point of view yada yada. I told them that most NPCs and one player (a paladin) will probably try to kill the evil PCs if they found out and they think about it as limiting their freedom to make a PC as they want.
But I don't feel like making a D&D world in which being evil is relative. If I want to make a campaign like that I will GM something like Vampire: The Masquerade, classical adventurers facing against evil and crawling in dungeons is what makes me want to GM D&D over other system that I usually play, and since besides the new DM I'm the only other GM, I would like to do something that is not the same as always.
What should I do? Change my campaign and world so they can play evil PCs without consequences or risk it and tell my players they can take it or leave it?