Over at Paizo, threads pop up fairly regularly asking how to run a PbP and I'm jotting down some thoughts about that here.
There are many more potential players than potential GMs.
GM dropout or burnout is responsible for the vast majority of PbP deaths.
So, how do you start one, how to you keep it running and how do you keep your own interest going?
However much you want to run a whole adventure path bringing the players from novice wet-behind-the-ears adventurers to super-charged world changers, accept right now that you can't.
Plan one adventure at a time. You can build from one adventure to the next and create a campaign that way, but if you set out to run all six modules of The Curse of the Crimson Throne you are setting yourself up for a world of heartbreak.
PbP is slow. In a three-hour live gaming session you can reasonably expect to get through at least one combat encounter and a certain amount of plot, negotiation and rambling around. In a PbP you may well be looking at 3 months.
Look at your material right now and prune it. Be ruthless. Read the adventure with a critical eye and ask yourself which encounters further the plot. Look at the maps and ask yourself which ones are necessary. On average, you will need to trim out at least one third of a pre-written module. If it doesn't progress the story, ditch it.
If you are running a homebrew, it's easier to make those cuts. However, it's your heart that breaks when all your carefully crafted subplots have to vanish. Trust me. They do have to vanish. You may be able to work some of them back in, but don't count on it. Running a homebrew requires a bigger investment from players and unless you live online, you can't possibly hope to answer all the questions that would take 10 seconds at the table and may eat a week of PbP time.
While this may seem like brutal railroading, be aware that the timescale of PbP means that a lot of plot points will be missed. If something is important, you need to say it loud and clear. And then say it again. Your players aren't stupid, but something mentioned in passing five pages ago can easily be missed. You will do yourself and your players a huge favour if you condense and telescope down to the essentials. If it matters, tell them.
16 archers may seem like a very cool encounter. Just be aware before you run it that updating those 16 archers is going to take a lot of your time. Maybe a couple of hours of it until the players start killing them. Consider reducing it to 6 rather more awesome archers.
Brutal pruning makes room for your players to build their own bits of plot. More on that below.
You will get player attrition. The chance of the same party existing in 6 months time is negligible. Keep that in mind and have ways of getting new players into the game without breaking the flow. Easy in urban settings, not so straightforward in the middle of a dungeon.
Run something you like or can turn into something you like. You will be looking at this baby for a very, very long time. Starting a game you're only half-invested in is doom before you even ask for players.
You've got your adventure. Now get your players.
At risk of stating the obvious, be clear from the outset. Include the following information as a minimum.
System - is it OSR, 4e, 3.5, Pathfinder, whacky thing you knocked up on the fly one drunken evening.
Starting level and character creation rules - self-evident, but important.
Setting - delving through the pygmy infested jungles of Rythortan is not going to require the same players as your high level diplomacy game negotiating with Grazz't. Players keen to build cavalier types will be justifiably unhappy if you don't warn them that they'll be spending a lot of time on boats. In an ideal world, any PC should be able to operate in any setting, but the reality tends to be that PbP PCs may only get the one adventure to show their chops. Don't let someone build a character they can't have fun with in your game.
Your own expectations - this is important. You need to state clearly what you want from your players. Posting once a day, 24 hour deadline or you get GMPCed in combat, notice of absence if possible. Whatever it is, get it out there. Corollary to this: stick to it. If you say you expect people to post within 24 hours of their combat turn coming up, make sure you do act on their behalf. (This is one of my rules and the one I try hardest to stick to).
If your game is something with obscure rules, can the potential players get easy access to them? If there's an online resource, post a link. Make it easy for people to find out about your game.
Tips to make your life easier
Ask your players to keep
track of their own hp and conditions and to make sure that they have a
complete character sheet available and up to date where you can see it.
If you need to run that character, you need that information.
asking your players if they will let you roll init on their behalf.
Time zones being what they are, it can take two days to get into combat
if you have to wait for everyone to check in and post. Nearly every
player I've ever met would rather post a set of cool things they've done
than an init roll.
If you provide maps, keep them updated. Players need to know
where they are in a battle. I use Flickr which occasionally refuses to
update properly. It's my biggest bugbear.
Try to post all the
information the players need in some easy to read format. If 16 archers
all attack, you are going to have to make sure that each of those
attacks is posted clearly. If any of those attacks have fancy effects,
you need to say so. Let the players know if they're injured or blinded,
or drowning in toxic mud without making them wade through an
incomprehensible paragraph. Like this one.
Running the game and troubleshooting
Assume everyone is an adult and wants to have fun.
Your primary job as the GM of a PbP is to be available and to keep nudging. Let the players know if you're too tired to post. Tell them you're going to be without internet for three days. Post regularly. You have to. If you keep checking in to see what the players are doing, they will keep checking in to see what's happened to their characters. It also means that if your internet does fry for some inexplicable reason and you can't get a message to them, they tend to know something is wrong and you haven't just abandoned them.
If you are burning out, losing interest or don't have time to run the
game properly, let people know. If it's a temporary issue, ask the
players if they're happy to accept a change of pace for a while - even
putting the game on hiatus if you need to. However terrible it feels to
make those posts, it is far, far better to do so than to jump ship
Be prepared to be ruthless. If you have a group of four or five great players and everyone is constantly waiting on a single laggard, you may well have to boot the offending player. You don't have to be rude about it, but you need to deal with the issue. Some players just need a different pace or a different game. You are not going to be the ideal match up for every player every time. Accept it and don't berate yourself.
You will make mistakes, so be up front about them. In general unless the mistake is completely game-breaking, don't try to revise it. Just suck it up and move on, implementing whatever it was you got wrong from now on. Similarly, if players make mistakes, sort out the issue as quickly as you can and move on.
One of the wonderful things about PbP is that you and the players can
develop characters much more organically and improvisationally than at
the gaming table. Suspension of belief is easier when you can't see the
large bearded gent playing the tiny girly halfling. This works both
ways. Players give you a lot of clues about their PCs through their
posts. Read them. Use them. It's game material on a plate. It is
free plot. Pick up on their randomly expressed thoughts, file them away
and use them. Make it personal.
Enjoy what your players bring to the table and let your own imagination roll. You have time to look up the rules and world-build, so use it.