NPC
A Non Player Character is a character under the control of the GM. They are there to provide backstory to a campaign, and to advance the plot or to un-snag narrative hooks. The role of the NPC is essentially to provide and infuse life to the game, so the Players have an avenue to suspend their disbelief (and ignore the fact that they are just a horde of sweaty guys in a basement with a bunch of dice). A world full of NPCs who are played well can lend credence to the reality of the world.
Sadly, this doesn't always happen, and the noble NPC is abused by many a DM who either doesn't know any better, or is a raging prick.
Types of NPCs
Inhabitant
These NPCs act as normal people would. Going about daily lives, maybe interacting with the characters, maybe not. They aren't spectacular in any way, but they're realistic. Like King of RPGs says, the GM doesn't just play the monsters, they play the millions of people in the game world that bear you no ill will whatsoever. This is a Good NPC, and, done right, can replace any other NPC on this list.
Quest Dispenser
Idiot cousin to the Inhabitant, this NPC waits around all day with their problem. They always have a problem, big or small, and they always just happen to be waiting for some strapping young lads like your party to help them out. Done wrong, they have little personality, totally helpless, and entirely necessary to begin or continue the plot as the DM has it laid out. This is a Crap NPC, but with a little work and imagination a good DM can turn them into a Good NPC by giving them, say, good reasons not to be able to help you out, or enough personality to make them enjoyable to watch. (Protip: Your questgiver is probably the most important NPC in your game, besides the BBEG, as he's probably the character your players will be spending the most time actually talking with. Entire essays have been written on this subject.)
Lackey
A dumb NPC that's there simply to take direction from the PCs. No free will to speak of, and is often used as a meat shield when danger arises. This is a Crap NPC. However, they make up your rank-and-file soldiers in the armies of the Player Characters and the villains when campaigns become campaigns, so they tend to be more acceptable then some of the other types below.
Hireling
Similar to a Lackey, but a bit smarter. They get surly and won't interpose themselves between the PCs and danger willingly. This is a Good NPC.
Merchant
A very necessary character, offering either items, services (such as buffs), or both. This is usually a Crap NPC, but as with the Lackey above, somebody has to fill the role.
Side note, and the reason for inclusion here: "Funny" DMs will sometimes imply that all the Merchants are the same NPC, or at least related, with the same "funny" voice. Only complain if the "funny" voice is really annoying, or if the DM tries to hang a plot hook on that idea, as while it's obvious and overdone, it's obvious and overdone for a reason (merchants can be some of the most boring NPCs to think up, the most likely to need to be thought up on the fly, and the Disembowel-Meself-Honourably Dibbler solution is at least a functional).
Psychopath
Fucked up for no reason. Brilliant in conversation, stupid in action. Exist solely to add 'flavor' to a DM campaign. Once in a blue moon, this NPC is tolerable. As a regular, he shifts from Crap NPC to Bad NPC. The archetype is given a free pass if they are player characters, though.
DMPC
The DM really wanted to play, and so made a character up. Only now, he's in control, so things tend to go the NPCs way. He will often be min-maxed, but arbitrarily so, as the abilities seem to change with the encounters as they require. This is a Bad NPC - unless he knows how to stay out of the way for most of the time, which usually doesn't happen. Gandalf is often accused of being the only Good DMPC. (Almost, actually Tom Bombadil was the DMPC, Gandalf was just an overleveled Player Character from another campaign that the DM let play anyway).
Then again, if the DM knows humility and the dangers of Mary Sues, these can be a helpful tool against inexperienced players or Hendersons.
Gary-Stu/Mary-Sue DMPC
As above, but with features that resemble the DM or his girlfriend. This is what the DM wants to be in his fantasy. There usually is a wall-o-text dialog from the NPC explaining his backstory, even if you just asked him for directions to a brothel. This is a Horrendously Bad NPC, and players are advised to be as subtle as possible in the execution of him or her, so the DM will only see what you did there after it has been done. And trust us, you will ALL want to kill this NPC.
Help with running NPCs
GMs often have difficulty using NPCs appropriately in their campaigns. Depending on the particular brand of GM, they might spend a disproportionate amount of time statting them or writing elaborate back stories, only to get killed or utterly bypassed by the players. They might also have difficulty actually role-playing a NPC who might only have had a limited role in their storyline, but the players keep going back to them.
So here are a few useful tips to remember for running your own NPCs.
- If you really have to give them a long-winded, poncy, made-up name, make sure you give them a title that the players can use.
- No-one remembers the difference between "Sunatela Estavros", "Donitri Kaliean" or "Likorian Goldmantle" but they do remember "King", "Guard Captain" and "Court Wizard"
- You don't always need to create the characters using the same method as the players; adding classes, skills and talents in order to "level" them to an appropriate match for the encounter. Especially if they are intended only to perform particular roles. It's easier to just use simple stat-blocks detailing hit points, any relevant saves, attacks and equipment.
- A GM controlled NPC doesn't need Knowledge or Lore skills but should have all necessary information relevant to his part of the plot. More can be added later if need be.
- When actually "role-playing" NPCs, sometimes it's easier to just play alignments rather than complex personalities. So you don't get stuck figuring out what a given character has to do when presented with odd situations the party inevitably generates. These are not exhaustive, but mean you don't need to have a spreadsheet of motivations at hand when players press an issue.
- Good NPCs are generally helpful, Neutral NPCs usually aren't interested in assisting unless incentives are offered. Lawful NPCs typically have reservations against social faux pas and antisocial behaviour, while Evil NPCs simply want to take the players stuff from them .
Player NPCs
Player controlled Companions, Cohorts, Followers and minions often cause nightmares for even the most accommodating GMs. Mostly because any opportunity the players get to create more characters they will use to powergame or munchkin the crap out of.
What's the point of having one balanced character who can help out in several situations who has an interesting back story, when you have a team of one dimensional guys who are unrealistically maxed out in single skills and have only ever done one thing in their life ever? This is natural player behaviour because even the most innocent person is not going to enjoy retreading the same ground with new characters, so will build new supporting characters with their primary PC in mind. In the worst case, you get exp batteries or crafting monkeys who do nothing other than selflessly make the PCs gear for them. But even in the most harmless of situations you get nameless dogsbodies who do nothing other than carry player gear around and act as extra inventory slots.
Some rulesets, like Saga Edition Star Wars or Only War do companion characters unobtrusively and subtly so that they cannot be broken and they end up behaving as an extension of the character themselves. While other rulesets suffer from creating their companions exactly the same way as PCs.
Leadership
One of the worst offenders is the 3rd Edition Leadership feat from D&D, which grants the player who takes it a major NPC cohort as well as a loyal group of low level followers.
The original ruleset explicitly stipulated that followers had to be generated from the shitty NPC classes of Commoner, Warrior and Expert and who never gained experience. Though the later 3.5 revision and Pathfinder missed that part out. The Cohort that summoned also comes in at several levels lower than the player, and gains experience at a reduced rate.
Many DMs simply ban Leadership, or any feat that grants cohorts and followers out of hand rather than deal with the hassle of a whole bunch of mini-PCs. Either that or they don't see the point in the feat if players can simply hire minions or gain additional companions through roleplaying.
Banning Leadership need not be absolutely necessary if the GM considers a few things or institutes a few conditions on what actually gets gained from the feat:
- Make distinctions between PC cohorts/followers and NPC hirelings/allies. The players have sacrificed part of their progression to gain companions or followers, so they should be able to have control over their minions. The feat is robust enough to apply penalties for poor treatment of followers so a player doesn't really need to consider the motivation of each faceless Lv1 commoner who works for him and shouldn't be betraying him out or leave him for no reason. An army of warrior followers who repeatedly get massacred by higher level monsters or forced to walk through minefields will result in progressively lower leadership scores and eventually lead to the player not being able to earn the loyalty of any more followers at all. Alternatively NPC hirelings or allies introduced via roleplay come with their own motivations and often work best under the control of the GM who can come and go as the plot requires it.
- Rule against any cohort or follower from taking Leadership or any kind of follower/familiar/companion through class features. This is simple common sense as it restricts the amount of paperwork you and your players need to do with getting essentially double the number of followers for free. (the Mastermind Prestige Class from the Rokugan campaign setting is an exception to this, because it's a class built for followers)
- Those followers have to come from somewhere, so it makes sense to reinstate the condition that followers be Commoners, Warriors or Experts who represent your "average" person in most locations. If you walk into a city and start recruiting, you're not likely to be able to find fifty level 1 Wizards, Paladins or Druids unless you also have the allegiance of a major knight order or arcanist guild, which will require a roleplaying element anyway.
- On a similar note also restrict racial choices for cohorts and followers to those relevant to the available setting, you are not likely to find 145 Drow or Tiefling Experts in a city of mostly humans and dwarves.
- Don't allow point buy or random dice rolls for followers ability scores, just use a simple non-heroic array (even a base 10 in all stats could work) so you don't have to track character sheets for each and every faceless and nameless minion.
- Realise that as players increase in level, so unless you are using kingdom-building rules and creating armies for massed combat, having low level followers become less and less relevant and are more likely to get relegated to background or labour positions like running farms or providing base security.
- Cohorts are, by nature, just low leveled PCs, so can suffer similarly to followers in that they become irrelevant in encounters with high level opponents. However, some players will get around this by relegating them to do nothing but buff and heal the party. This is not a terrible thing in itself and some inoffensive alternative classes choices (such as the Healer) can be encouraged.
When Things Go Wrong
Sometimes, NPCs do NOT work out like the GM planned. One of these stories is the one of Kren and Frep, two NPCs in the authors Rogue Trader (RPG) group. Kren and Frep were just basic fleet armsmen, armed with mighty (...not) shotguns and wooden fighting sticks. They were "introduced" when two random dudes standing in a fleet dock were admiring the ship of the players, who proceeded to instantly hire the two.
GM: well, fuck. (now i have to think of stats and stuff...)
Anyways, they ended up carrying a large medi-kit and a life-saving backpack for the party around, following them and doing not much else.
They were just following the PCs and discharging the odd shotgun shell. They even managed to kill some random cultists with their wooden sticks after some lucky rolls.
In one mission, the party was on a derelict ship, and they were constantly finding random stuff strewn across the floor, sometimes even weapons. One of the PCs found some guns he had no use for (he was a Kroot). And gave them to our valiant armsmen. A rare sort of boltgun and a best quality lasgun.
And then. All went to Shit.
Those two flaming assholes sure as hell DID roll multiple "righteous fury" when they hit the final boss of the mission, an Alpha Legion Chaos Lord, killing it with 64 wounds inflicted when he had 28 left. (Yes, the PCs DID manage to plonk off 2 hp before).
Originally, when creating the adventure, I intended to have the one who killed the Lord gain a special reward, and so thought of revoking the fact they killed him (like, they misfired or something), to give my group the chance of killing the bad guy actually themselves. But, after somewhat 15 minutes of everybody lying on the floor and almost pissing ourselves of laughter when we had realized what had happened, everybody agreed we'll let it stand like that.
Still, Kren and Frep get a full Henderson for this.
As a meme
Recently in 2018, NPC has been turned into a meme by the likes of a /v/ anon. If a person is refered to as a NPC, they are people who do not think for themselves or are incapable of having an internal monologue just like those typical rpg game NPC who can only respond to the player what they were programmed to say.
Naturally, this has also become associated with the usual suspects, due to being used as a means of trolling the other usual suspects - which means there's inevitably the usual subset of the peanut gallery that unironically believes no one other than them ever monologues to themselves. The irony of the situation is not lost on observers who aren't too busy being assblasted.