One of the more difficult things for the gamemaster is creating and fleshing out interesting characters for the players to interact with. There are a few ways to make your job easier. First, recognize that not everyone the player means needs to be heavily fleshed out. Think about an average day for you: chances are most of the people you meet don’t give you a whole CV and sense of their motivations in life. The guy waiting on you at the bar, or ringing you up at the store is polite or not, friendly or not…you’re interaction with them occurs in a matter of minutes and is done. Similarly, most of the interactions of your character with folks are going to be cursory.

Think of the NPCs in movie terms — there’s the extras that fill the scene, there’s the walk-on speaking role (“What can I get for you, stranger?”), there’s the bit player (the background character that pretty much does one thing for your characters), and the supporting. Your players are the main cast.

Extras — these guys are just set dressing. Describe in thumbnail terms these folks — “There’s a crowd of shoppers in the mall, mostly teens jabbering on their cell phones or to each other…” or “As you enter engineering, you have to dodge a bunch of red shirts carrying parts and tools…” or “The street’s full of tourists walking to the beach or sitting about the cafes that line the esplanade. A few police are directing traffic or loafing about flirting with the ladies..” Unless the players take notice of something and inquire, leave at that. If they inquire, you can expand a bit on the description but unless they engage directly with a character, they’re just extras.

If they do engage with an extra, they are a walk-on speaking role. This is the shopgirl, the barmaid that you flirt with but don’t really get to know, the guy that helps Scotty and McCoy stop Kirk from going into the radiation-filled chamber in Star Trek II: The Wrath of Khan, but usually its the guy that directs you to the bit player or supporting cast. they might have a name, if they turn up a few times, a basic description (red haired kid in Colonial deckhand coveralls…you think her name is Callie or something like that.) At most they have a hook — a name, a job, some vocal or visual cue that makes them more than an extra. (Bicycle girl in the first episode of The Walking Dead would even count for this.)

Bit players, like the walk-on, are pretty one-dimensional, but if they catch the players attention, they might get called on to aid in the mission more (rising to supporting cast.) These are guys like the coroner your detective has to interact with, but whom really don’t know that much about other than his/her name, a basic personality (moody, cheerful, stand-offish, etc.) to help the PCs interact with them, and maybe a basic set of stats that might come into play. They don’t know more than a few tidbits about them (single or married…maybe you know the spouses name at best; they’re into cats or dogs from a photo on the desk, or something like that.) Keep it simple, but these are the NPCs, I find, that people latch onto and start wanting more from…that’s when you need to start building more onto them on the fly. Take notes on what you did with the characters so you can start building them up to…

Supporting cast: these are the NPCs you need to put some work into and cover everything from recurring NPCs (say, that cop in the stationhouse that you always tell to get you the file on whatever) to major henchmen and villains. For the lower end, say your favored mook, you’ll want a real basic idea of what their physical and mental abilities are, their big skills. Some very basic background and character elements. (Singh is a Sikh that deserted from the British Army in India and came to Shanghai where he is now your favored bad ass. He wears the turban, bangle, and carries the knife of a Sikh, and has almost no sense of humor that can be detected. Women love him.) For the more important supporting cast, say the captain of your starship, you have the name and stats written up like a PC (build to the ideal of the character, don’t bother with creation points unless you like to build characters…like I do), basic background that people would know, and a more fleshed out personality.

Important to note is that your major villains don’t always need a big background — you might know that Hanoi shan was a native colonial administrator for the French in Indochina, and that he was suspected of collaborating with anti-colonial forces; that he likes to use poisons to kill his enemies and has female assassins; that he is super-intelligent and well-educated. With that you can already build a good picture of the character without having to know what his relationship with his mother was (unless that becomes an important aspect of the storyline.) However, you’ll want a full writeup of your major villains, and probably their top henchman, as well. (Think James Bond movies for this — the big baddie rarely gets into it directly with Bond, but his steel-toothed henchman, or femme fatale will…you should have an idea of what they can do in a fight or action sequence.

Only put the level of detail and work into the NPCs that you have to, but be prepared to add more on as you go; you never know when the character is going to decide that cabana girl is the one for him.