As a DM I reserve the right to tell people that they are not welcome at my table. I put in too many hours of prep to have it ruined by douchebaggery. There are polite ways to say it of course and I always take that route but ultimately you have to be your own advocate and take care of yourself. No one else is going to do it for you.
Tell them that their playstyle/behavior doesn’t work with your own and unfortunately you no longer can continue as their DM. Thanks!

I’ve dealt with similar issues several times over the years. You did the right thing by first handling it privately, one on one. Telling the offending role-player that if the game isn’t fun for everyone, something should change might help, as will the actions of the rest of the group as a whole.

I can excuse some disorganization or spotlight-hogging if the person is otherwise a team player, but someone who puts down others, too often goes on tangents in conversation, or can’t handle the occasional setback will eventually degrade everyone’s experience. Even the best players (and G.M.s) can fall into unhealthy or annoying ruts.

Sometimes, it can be rationalized in character, with the problematic character eventually being shown the door by an adventuring party as their styles and goals diverge. But in general, it’s better if the Game Master is candid and tries to deal with difficult gamers directly.

I used to post the following “rules” regularly as a reminder:

>>Rules for Role-Players

1. Feed the Game Master — please bring munchies or money for food to share.

2. It’s only a game — it should be fun for everyone in it.

3. Distinguish between your “voice” and the Player Characters’ personae. Use the latter in the game as much as possible.

4. Even if the P.C.s aren’t working together, role-players always should cooperate.

5. Every P.C. is unique; personality is more important than statistics.

6. The rules and sourcebooks are only guides; imagination is more important than dice rolls. G.M. rulings will be made as questions arise, but final decisions will be made between sessions.

7. Creativity and patience are rewarded within the campaign by social connections rather than by mere power increases.

8. While enthusiasm and humor are necessary, “cross-talk” is to be discouraged.

9. Experience points are distributed between sessions, based on attendance, cooperation, notes, participation, and imaginative role-playing, not just combat or foes slain.

10. Please keep your P.C. records and notes up-to-date and provide copies to the G.M. They will be shared with the rest of the party at the G.M.’s discretion.

>>For Player Characters

1. Step one — create a diversion! When in doubt in a tactical situation, distract your opponents. 😉

2. Most Player Characters start out with little knowledge of the campaign setting. Curiosity and an open mind motivate most travelers.

3. Nothing happens unless the Game Master is aware of it. P.C.s only sense through dialogue and the G.M.’s descriptions.

4. P.C.s are not aware of and should not discuss attributes, alignment, or combat statistics. They should keep track of where they’ve been and whom they’ve met.

5. P.C.s are never motivated to gain more points. Greed is common, but most adventurers seek acceptance into the ranks of experienced heroes.

6. Unless the party is certain of others’ intentions, it is wise to ask first and fight later. Even soldiers avoid combat, and mystics often prefer study to fighting.

7. There is always someone bigger or stronger than you.

8. Parties should choose a name and a nominal leader. Standard operating procedures (S.O.P.s) make routine tasks quicker.

9. Rational debate is good, but most personality conflicts aren’t.

10. Do not test the will of the gods.

These are pretty old-school (I think I first wrote them when running AD&D2), but I hope they help!

I’ve never written out a formal list of rules for the social contract … but, something you definitely need to do is:

Set Expectations

There is no universal set of rules for the game table. For example, I have _never_ been in a game group where it was a hard and fast requirement that you bring your own pencil and dice. Yes, it was a good idea, most of us did it because we’re proud gamers who want to show off our own dice set (and quirky geeks that don’t want to share our favorite writing implement). But, if someone forgot or something? no big deal. (on the other hand, people rarely forgot, in my gaming experience … if they did, they almost never did so two sessions in a row; but again, not because it was a social rule, but because we all liked to proudly have our own quirky gamer kit).

My point is: no one knows what YOUR house-rules are, until you tell them (meaning literally rules for your house/game-table and not custom RPG rules). They can’t/shouldn’t be held accountable to rules that haven’t been expressed to them. If you do, then you can/will come across as being arbitrary.

The luxury we have with long-standing game groups is that those rules probably came out organically as you went along (one day, Fred spills a soda and almost wipes out all of the character sheets and an expensive game mat … so, everyone nods and says “no more drinks on the game table” — no one needed to be heavy handed about it, it was just all mutually agreed due to a common bad experience). It wasn’t formal knowledge, it was tribal knowledge. And because it was arrived at mutually due to experience and observation of things that work well for the group, none of it was by fiat and everyone felt comfortable with it.

In a new group, your tribal knowledge from a previous group is a) not part of the current tribe, b) not known to the current tribe. Thus, your tribal knowledge and expectations due to previous game groups are … not really applicable.

I hope this isn’t coming across as negative against you. My point here is not that your rules are unreasonable, but it’s that you need to communicate your expectations to the group. And, until you do that, it’s not fair to expect them to conform to those expectations.

And, one other thing to consider is: if any of them have gamed with each other before, then they might have their own tribal-knowledge about appropriate social conduct that isn’t the same as yours. And as individuals, they might have similar unique thoughts about social conduct. Another reason you need to communicate your expectations … and be prepared to compromise if the group as a whole has a different expectation.

(but, if it’s your house, your table, your game mat, and things like that, you don’t have to compromise completely … protect your property and the environment of your house, but realize that not everyone has the same rules about things that aren’t explicitly about your house — like the thing about bringing your own pencil)

It sounds like you just need to talk to him…like, face-to-face, if email is not something he checks frequently. I don’t think there’s any need to write all these rules down or otherwise trumpet all this fanfare about who brings what or does which. The bottom line is this: if he’s disrupting the fun of other people (especially you), you owe it to everyone, including him, to talk to him. Either he agrees, corrects his behavior, and everything’s cool…or he disagrees, leaves your table, and everyone is happier for it. Either way, you win! So talk to him.

When I decided to run my first and current long-term campaign, I went through all these things before starting to make sure everybody would be comfortable.

We covered snacks, attendance, language, alcohol… and yet, to this day, I find myself wishing we had discussed some issues that come up occasionally.