Quote from DnDPaladin >>

There is literally only 5 DMs that we know of in my area for literally 100 players. Regardless of where you look there is always a lack of DMs. So what you are telling me is that i should not mix my fun even though its easy to do. What you are telling me is to stop what i love... Dming to do another i love... Playing...

Again as a dm... Its easy to do both... Because you already do it on a constant basis... The only question id have to ask you is... What the big difference between a full pc and a barely fleshed out npc if not a severe lack of abilities ?

I agree. It's the same thing, just one doesn't have a character sheet. I don't see why some people think no one should do it. It's just like any other sort of table rule. It obviously works for some tables, not all.

I personally consider every NPC, every good villain, every shopkeeper, and potentially even monsters to all be characters the DM plays. The DM in many ways, plays the entire world the players are in, and so they do get their fair share of 'playing a character', it just may not always be a static player fighting alongside the other players, but that doesnt mean the DM doesnt have their own creation to call their own. 

It really depends on the DM you have.

First, you should discuss with your group about having one in the first place - make sure everyone is on the same page. Concerns and such will be brought up, so then you will get a better feel of how not to step on the toes of the players.

Ultimately, I think that you need to have a very strong sense of DM knowledge and character knowledge, and keep them separate. You need to make sure the practice is going to be ok and acceptable by the group, and what kind of role they'd want you to play as a DM PC. Then, if players change their mind, you need to be willing to change to accommodate this.

There has been so much said here already, I'll just add my 2 cents. 

Cent #1: I've only been playing RPG's for about 7 years now, and very sporadically (work and finding a group made it hard for a while), but I've played with at least 6 different DM's in as many systems. I've had DM's that were awesome story tellers, DM's who were great at understanding the rules and the flow of the game, and DM's who were great at both. I've also had DM's who were pretty terrible at understanding the rules and put handcuffs on your character's ability to interact with the game. All that said, I've only had one actually bad RPG experience, and it was due to a GM with a GM-PC. Not to go into too much detail, but during the entire session the rest of the PC's were a bit of a sideshow,  got to make no meaningful decisions, were railroaded into being captured, had several creative ideas on how to escape and were told that each failed, and then the GM-PC came in and rescued everyone with a big explosion while going, 'looks like I have to bail everyone out again'. THEN in the aftermath, the GM literally had us all roll a D20 and whoever rolled highest 'landed near' the McGuffin we were after, and we all ran away. 

Now, I think you can make a strong case that this would have been a terrible session with or without the GM's PC. But it was pretty clear that the rest of us were there to provide flavor and background and an audience for the story they wanted to tell about their character, as opposed to actually crafting a shared story for all of us to enjoy. So if you are going to have a GM-PC, please carefully examine your motives and be really, really honest with yourself (and ask a friend who is playing to be honest with you too). 

Cent #2: I'm brand new to being a DM, and I know there are a lot of different DM'ing styles out there, so maybe some people find it really enjoyable to do both simultaneously... But right now I am enjoying DM'ing so much that I don't really like I need a character myself. Part of that may be because I have a second group I actually do play in (with a different GM)... but between the two, I actually really enjoy DM'ing more and don't feel that anything is missing from the experience. 

on your cent #1... i'll simply say this... with or without the GM PC, you should have dodged the hell out of there once you realised the DM wanted you to be a spectator to his awesome characters. there is nothing more bad then a DM who says my table my rules my game not yours ! thats the worse DM you could get. and that would of hapenned with or without the GM PC.

on your cent #2... that's exactly the point i was making as well... you are used to have NPC who are just as much as a PC then you think. and if the players ask one of your NPC to come with them, are you gonna do what the other GM did and just say no because whatever reason you dont want that NPC to go along ? the rality is, pretty much all NPCs are gonna interact witht he story as much as the PC does. and any DM are prepared to go that far if anything goes. sure its ultimately the players choice to bring or not an NPC. but reality is, if you create a strong NPC with a backstory that brought him there, there is no reason for the PC once they figured that one out not to bring the guy along. or you could go the stupid road where all of your NPCs are helpless citizens who needs savings. but to me that is unreasonable considering the world you designed is a dangerous place and the weak shouldn't be able to survive if everyone, except players, are helpless.

i could give you numerous exemples of why a capital city is the worse place for players to try and be murderers.
in my world there is no way a capital city do not have anti-magical prisons, there is no way a capital city do not have clerics with high enough powers to be able to ressurect people, there is no way that same cleric cannot scry whenever he wants, there is no way that same cleric isn't employed by the kings of the regions. basically.... there is no way this city do not have levels in it. which is what i find lacking in mnay many a DM arsenal. it seems those people think leveling is only availlables to players and thats my primary concern. it makes the world much less immersive to me.

i'll take my world for instance...
Vesthéa : Realm of Immortals
basically, every rulers in my world is a level 20 charcater. with immortaility and a bit more powers to them as they are revered by the populace. trick is... in a capital city. there is 1 immortal, sometimes 2 but rarely more. their champions are usually between 10-15 and the city guard are anywhere from 3 to 10 depending on their titles. milicia are always between 1 and 3. now there are blacksmiths there are profession people and they also require a level... i mean sometimes, rarely you do get a veteran fighter who decided he had enough and got the life he wanted. basically your NPCs have a life too. if not, thats just outright non-immersive.

happenned to me a lot that npc started with an ideal, a bond, and a flaw, yet now they are fully flshed out characters with stats because of what players did. and the fact that the said NPC would join a fight to defend its establishment. so my question is this simplicity to you as a new DM... do you really think there is a difference between your NPC and your PC ?

As a genral rule u can have an NPC in the party but its best if take a back seat

Its hard to take a back seat in many situations and again it breaks immersion. Imagine the king his clerics and his army not going into a fight because hey heroes. There is a difference asking frodo to go with the ring while the others wage war against sauron. But asking boromir not to care for gondor because others can do the job would of been very very subpar.

Sorry but if a dragon attacks a city... The guards and the dirigeants will fight it. Heroes or not ! There is no way heroes can convince the city guard to take a backseat for heroes to gain fame.

Hey guys, I saw different opinions in the thread. Here are my 5cp. I am running a campaign for brand new players. Also our group is very small for now. Having a DM character serves multiple functions:

• The DM character balances the party. The party is very small, I even had to bring some NPCs to help in battles. And no, I am not going to reduce the difficulty to my party size, as it will take away from the adventure the PCs got themselves into. Also, the PCs are aware about DMCs abilities and in the most cases command the DMC on the battlefield. 
• The DM character class is different from other group's classes, which gives an opportunity to try different approaches to adventuring.
• The DMC has an interesting personality that keeps the group entertained. It can be a hook to a quest or some interesting development, if party chooses to pursue that. I throw some hooks from time to time and see if the group is interested.
• The group can come up with some of the DMC's personality. This allows the new players to understand a concept of role playing, instead of playing themselves.
• The DMC is one of the Deus Ex Machina, It allows me, as a DM, to help, usually with an advice, in a lot of situations my party can get themselves into. From taking a dumb action with potentially severe consequences to simply idling. This is not to restrict PCs, but to suggest what might happen. My players have experience of playing computer RPGs, so they have a certain bias towards what they can do in DnD.

AssGuardian..........best username I've ever seen.

I personally don't think I'd be able to handle it. It's a ton of work, and as is, I'm multitasking. But the way I've set up my campaign, I have the main character as an NPC that I play, and it's a lot like having my own character without all of the problems that come with trying to be a PC and DM at the same time. Dante (my NPC) is very much the main character, and he's definitely not a PC, but he's very similar in a lot of ways. He fight alongside the characters, he heals them, he investigates, he does exposition. He's basically their Gandalf. I've heard from multiple players that they love having him, and it allows me to put them up against bigger things and move at a little bit of a faster pace. Overall, I think having a Gandalf is a happy medium. 

Quote from DnDPaladin >>

Its hard to take a back seat in many situations and again it breaks immersion.

On the occasions when the story calls for me to bring an allied character into the game, I make it clear to the players that he's just along for the ride. He won't participate in the decision-making process for driving the story, although he will fight in an appropriate way when the situation calls for it. I wouldn't want to take on the extra work of having a character in the game for very long, but it's pretty liberating as a change of pace. I don't find that it breaks immersion at all when I establish the scope of the character's participation upfront.

The problem is that it does break immersion if your character just follows around leaving all decisions to the group... As a player i find it ridiculous when i try to get a characters impression of a situation and all i get is... I think the same as you. Or ill follow your lead even though i dont like it because you are the hero and not me.

Sure it is never said that way... But it is still the way i see it. Take sam gamji in lord of the ring... Definitely an npc along for the ride... But his opinion is definitely sought after by frodo. And when shove comes to push he does have his occasionnal moments of glory. Which is pretty darn fine. Same with han solo in star wars who is just an npc for quite some time. But look how it turned out. He did have some moments to shine...

I think the biggest problem in stories is that the world must be living and in video games most of the time the game isnt. Thats why you guys think NPCs have to take a backseat... Because you think video game... Npc in video games never do anything exceptionnal. But in stories like movies or books... With the right reasons... You could persuade han solo of coming with you and participate. Heck even interact with the damsel in distress. 

As a player... Im not asking you to become a hero with us. Im not even asking you to follow up afterward... But i do require your characters knowledge. Your skills to be used and definitely your opinions... Otherwise why would i even acknowledge you at all ?

As a dm... I strive to give a living world to my players. A world where npc do have motives. They do have lives of their own. They arent just quest givers you know.

Thats all im saying. If you cant differentiate knowledge from one char to another though... I wonder about your ability to dm. This is bread and butter. The basics !

I just don’t think you can apply a subjective statement like that universally. A character I bring into my own story is (so far at least) necessarily one-dimensional and exists to serve a specific purpose before leaving the story. The players at my table understand this and don’t expect deviation from it. That’s why there’s no problem with verisimilitude when such a character appears. If the players do not initially trust the character, then the examination that follows enhances the character rather than diminishes it.

I think there's a couple of distinct classes of NPCs/DMCs being batted around here.

Complexity Breakdown

1. The one dimensional support cast member: Primarily meant to fulfill a role in the narrative - these are the shopkeepers, quest givers, low-level stock bad guys. They're pretty much one-dimensional, can be summed up with a single motivation, a brief physical descriptions, and 1-3 quirks to keep them distinct from all other other supporting cast members.
2. The complex NPC with motivations: These are major ( possibly reoccurring ) NPCs, which have more nuanced motivations, and more complex personalities. These are the NPCs which the Players will remember, and can form lasting on-again-off-again relationships with the Party. They are along for the ride with the Party because their goals and the Party's goals coincide for now. They have multiple motivations, multiple stable personality quirks, and are written to be interesting and memorable for the Party. However, their motives and goals are their own, and seldom change ( but if so, do so on their terms, not to mesh with the Party ).

Role Breakdown

1. The DM sockpuppet: This is a Party tag-along the DM plants to feed information and motivation into the Party. If executed well, they're complex NPCs who work with the party, and provide the information as part of their character expression and pursuit of their goals.; if executed poorly, they're simple one-dimensional characters who really don't have any other role than to pipe up occasionally and oracularly feed the Party a clue when they're stuck.
2. The Support Specialist: Provided by the DM to plug tactical holes in the Party build. They may, or may not, be a sockpuppet - but I think there's a real temptation for DMs to use them as one. Again - they can be executed well as complex NPCs, and executed poorly as faceless one-dimensional "hired swords".
3. The Party Handler: This is the sockpuppet on steroids, and a problem category. This is where the DM tries to exert control over the Party, by feeding them the clues to steer the Party down avenues that the DM thinks the Party should go. Party Handlers are often used for Railroading the Party down the narrative choices the DM wants the Party to pursue.

I think that when most DMs envision a DMC they are picturing the Complex NPC with Motivations - and many people fear that the DMC will become a Party Handler.

I think the trick from keeping the former from lapsing into the latter is to play the NPC according to their internal motivations, and not according to the DMs belief as to what the Party needs. This means that running the DMC as Complex NPCs is probably safer, as their internal motivations are explicitly spelled out.

If the NPC is being "true to Character" then they can be a ( subtle ) Sockpuppet  and/or Support Specialist without falling to the dark side of being a Party Handler.

It's generally considered a bad idea to run with a DMPC (by which I mean, essentially, a non-player character who is a member of the players' party) because you could be seen as trying to overshadow the players. There are some interesting things you can do with a DMPC - for example, two people I know are co-running a game where there is a DMPC who's going to turn out to be the main villain, and is currently a level 12 sorcerer pretending to be a level 1 sorcerer. This character certainly has the power to overshadow the PCs at any moment, but the DMs are (from what I know) conscious of this and deliberately trying to make the character relatively useless so as not to overshadow the other party members. But of course, this requires the players to be okay with a DMPC existing in the first place - there is a stigma associated with it because of how badly it can go wrong.

Beyond that, just remember that every non-player character is the DM's character. By definition, as the DM, you will be running characters. You might want to build out prominent NPCs using the PC rules, giving them class levels and such, if character-building is what you're interested in. The freedom to alternate between using the PC rules and writing out your own freeform statblocks is a nice perk of DMing - just obviously don't let that authority run away with you because the PCs are the protagonists, and the NPCs are the supporting characters - otherwise most players will feel that you're cheating them.

With full respect and politeness to everyone involved, we need to speak for ourselves here. Whether or not we individually may be able or comfortable running a game in a significantly more complex manner while preserving immersion and fairness to the players is irrespective of whether it is possible. It takes skill, experience, and tolerance for extra work to pull it off smoothly.

Quote from TexasDevin >>

With full respect and politeness to everyone involved, we need to speak for ourselves here. Whether or not we individually may be able or comfortable running a game in a significantly more complex manner while preserving immersion and fairness to the players is irrespective of whether it is possible. It takes skill, experience, and tolerance for extra work to pull it off smoothly.

This. This is what I've been thinking while reading some of these posts.

Ultimately this really does come down to personal preference. I had been running my DMPC’s as bog standard NPC’s for the last year of game time. My players have adored my DMPCs more than any other characters in the game and they’ve never had a problem with them. One of my players even started a romantic relationship with one of them and another rolled a new character so that they could be related to one of the other DMPC’s. I dumb down their stats and narrative opinions when I can but for the most part when the players want their opinion I give it.

Recently I talked to my players about this topic as it has been bothering me for a while. I record all my games so I know exactly how much time I’ve DM’d. Right now in our main campaign alone we have played 213 hours with me as DM, and that’s just the recorded stuff. I would almost double it for out of recording time. I have spent all that time DMing and you know how much I’ve gotten to play as a PC... 0, nothing. No one else wants to DM or can’t DM at the level that I do which is totally fine.

So I brought it up to my players and they asked why I dumb the DMPCs down. They weren’t offended that I had a DMPC or that I wanted to play. They were bothered that I was holding them back. I am now planning on fleshing out my main character a bit more so he can be part of the group in a bigger way. All of this because MY PLAYERS wanted it.

Ultimately I think that if you are really worried about it just talk to your players like I did. On the other hand if you are here to ask the question on if you should make a DMPC, I say try it out! The worst thing that could happen is you find it too stressful and you just turn them into an NPC and move on. Love your players, Love the game, and have a happy new year guys!

Quote from TexasDevin >>

I just don’t think you can apply a subjective statement like that universally. A character I bring into my own story is (so far at least) necessarily one-dimensional and exists to serve a specific purpose before leaving the story. The players at my table understand this and don’t expect deviation from it. That’s why there’s no problem with verisimilitude when such a character appears. If the players do not initially trust the character, then the examination that follows enhances the character rather than diminishes it.

 Only if your players at your table are there only for stories like spectators to your brain... Mine on the contrary... Like that every npc has a life. They love the fact they are not restricted to the story i made. In fact... I gave them hook for the astral plane and they simply didnt want to go there. They love to have choice that actually matter... You know... Not just me playing ping pong while giving the false choices. Basically im offering true open world.

Im not saying bad experiences do not happen... They do and its unfortunate... But generalising to say dmpc is generally a bad thing and npcs... I have none that are one dimensionnal... They are all more then that. Thats why my players loves my game. Because its alive. Not just a serie of scenarios we read in a book !

A dmpc to me... A guy who flesh out even on the spot characters... Is the very same as playing any pc... The only difference in all of it... Is that i need to concentrate on numerous pcs while as a player i have the liberty of playing a single one.

Generalisation based on bad dms who are too new or who simply just want to be gods is what makes people afraid of playing or even dming !

That response seemed needlessly judgmental. Limiting statements like, "Only if your players..." and hand-waving alternative storytelling styles as "bad DMs who are too new or who simply just want to be gods" comes off to me as a bit myopic in an open conversation about the merits and risks of DMs with a character as part of the adventure. You want to present a rich character as part of a broad and open world and it seems like it works at your table. I want to present a small DM character in my stories who functions simply as a plot device and who steals none of the story's spotlight from the players and I'm sure that works at my table. To say I cannot do so without limiting my players' agency in the greater story would be uninformed since you're not at my table and you don't know me or my players. Furthermore, it threatens to limit the overall thread discussion with absolutes.

I suppose it's like saying there's a right and a wrong way to write a novel. There may be narrative styles that someone likes or does not like, but if the reader (or the player in our discussion) leaves satisfied, the story did its job, as did the DM character within the story.