Long post, but here you go...Top 10 Tips I Have Learned GMing and Playing PbP
Probably the first lesson learned I will pass on is to remember PbP is an entirely different medium than face-to-face and it would be a mistake to try to recreate a face-to-face gaming experience in a PbP game. Too often I have seen well intentioned GMs try to replicate tabletop play via forums and it usually results in a game crashing and burning before it ever gets off the ground. Play by Post is an excellent medium to get your roleplay fix, but it works best when you treat it as its own thing.
So with that preface out of the way, I will lay down what I consider to be good rules of thumb to set-up a successful play-by-post game. Please note, these are my opinions based on experience running in this medium. For frame of reference, I have run five different PbP campaigns, all of which lasted 2-4 years and were actually completed. 1. Tear down the GM Screen with regards to combat resolution.
Most PbP GMs approach combat in one of two ways: 1) players roll their attacks/damage/etc. and then wait for the GM to adjudicate after the fact or 2) players describe their actions and GM rolls for everyone at the end of the round, adjudicating in isolation and then describing results.
Both of these approaches are problematic. The first slows an already slow medium down even further, as players are forced to wait for days at a time to determine whether they even hit or not. Additionally, this first approach places all the work on the GM to crunch 4-6 players' rolls, in addition to the rolls of the NPCs, monsters, etc. This is not fun for the GM or the players. The second approach exacerbates the problem even more because the players have lost agency on an enjoyable aspect of RPGs--rolling dice, virtual or physical. Secondly, it still puts the GM in super-computer mode to synthesize everyone's actions and put together a coherent narrative of what happened. Every round!
My recommendation is to provide the players with enough information to resolve their own actions, without having to wait for the GM to determine whether they hit or not. Players roll their own attacks and damage and can immediately tell whether they hit or miss, and narratively include this information in their posts. To do this, all you need to do is provide AC and hit point information for the different enemies they might face. Sure it takes away some of the "mystery" of not knowing a foe's strength, but it more than makes up for it in allowing the game to move along at a good pace. For boss-type and unique creatures, etc. you can keep the AC and/or HP a mystery to heighten tension, but for most mooks, this is overkill and adds nothing to the game. Most players have a good idea of a standard creatures AC and/or hit points anyway, because they have access to the same books the GM has and can figure that stuff out on their own. No need to drag a game out just to maintain the illusion of the players' not knowing a monster's abilities--they know.2. Initiative.
Another aspect that can kill a game's inertia is initiative. PbP is not the right medium to have people acting in individual initiative. Too much time can be wasted between initiative counts waiting for players to log-in and post. My recommendation for initiative is to either do group initiative or stage initiative. Group initiative is self-explanatory. Stage initiative is when you have three stages: Before Monsters, Monsters and After Monsters. Everyone still gets to roll initiative, but can post at any time during their stage. This approach can also slow down play though, so as a GM you have to be ready to roll initiative for players to ensure the game moves on without waiting for a single player to roll initiative before you can even begin the round. Whatever you do, keep initiative simple.3. Advancement.
Jettison by-the-book XP awards. PbP takes too long to mess around with an XP pace that assumes people are sitting down in the same room playing at the same time. My recommendation is to award XP as normal, but do not divide it among the group. Everyone earns full share of the total XP. Using this method, it is reasonable for characters to earn two to three levels per year of an active PbP. If you play it by the book, you might spend an entire year gaming without anyone earning a level.
Players like to earn levels and will grow discontent if they're not seeing character progress. Alternatively you can tie XP to completion of adventures, plot points, etc. and manage level gains this way. In either case, you want to make sure players are earning levels and not stuck with 1st level characters for a year or more. Many are the crash and burned PbPs with a stable of lean, hungry, 1st level characters.4. Adventures.
Many PbP GMs have grand ideas about running entire adventure paths or even single modules. They get this great idea that they are going to run some megadungeon or epic campaign arc spanning multiple modules. I can tell you from experience this is also a recipe for a game to die.
With active players posting every 1 to 2 days, even running a "short" 28-page adventure might take 1 to 2 years to complete...if you're lucky. My recommendation is to keep your adventures short and episodic. Sprawling dungeon crawls are not meant for PbP. Trust me on this one.
I typically run adventures that feature about 5 to 10 challenges. Tops. This will take anywhere from 6 to 12 months.
If you have your heart set on running a particular published adventure, try to cull those essential parts of the module into a condensed version of itself, separating out the "resource wasting encounters" from the meat of the adventure. Resourse wasting encounters only serve to add unnecessary time to a game and should be eliminated.5. Communication.
Cultivate a community with your players by having an active out-of-character thread. Get to know your players so they are more than just players in your PbP. Developing relationships with your players may mitigate the likelihood of players just disappearing when "real life" happens. At the very least, they might be more inclined to let you know when real life will have them sidelined, as opposed to just disappearing with no word, leaving everyone waiting around for their character to act.6. No Character is pivotal to a story's completion.
Related to the last point, you will lose players due to real life. There are numerous reasons why this will happen, but the bottom line is expect attrition. For this reason, make sure your game does not hinge on any particular character.
Odds are, that player will get ambushed by real life and disappear at any moment. Be ready to move on, either recruiting a new player to take over that role, or phasing out the character altogether.
Suspension of disbelief is huge here. Their character just fades to the background. Most players will want to create their own character anyway, so you may have a hard time finding a replacement for a particular character. New players are easy to find. New players willing to take on an orphaned character...not so much. Don't build your game around any one character.7. Minimize time-wasting "getting to know you" and down-time activities.
My recommendation is to jump start a game immediately with action. Avoid the "you all meet in a tavern" stuff. It wastes time at the beginning of a game. I can't count the number of games I have seen start out this way and never make their way out of the tavern due to the game imploding.
Once the game is established and the players know one another, you have an opportunity to do more of this kind of stuff, but in the beginning, you run the risk of the game derailing and never getting off the ground. On a similar note, down-time activities between adventures should be handled narratively, as much as possible, as opposed to role-playing every interaction with NPCs. You can spice things up with a few role-played vignettes, but there is only so much value to RP'ing with the smith over the going rate of swords in a given town. Keep this stuff to a minimum.8. Keep the Party Together.
Splitting up a party at the table is bad enough, but it's even worse in PbP. At this point, you are forced to then run multiple instances of the game to ensure everyone is engaged. If you have players sidelined with others are off doing their own thing, you run the risk of losing players due to inactivity. Engaged players makes for reliable, consistent posters. Try to keep the party together as much as possible.
9. The Roar of Lull of PbPs. When a new game starts up, everyone is excited and posting nearly every day. It can quickly become overwhelming to a new GM. This usually settles down after a couple of weeks, but expect a tidal wave of posting activity initially, and don't be afraid to throttle back a little bit to keep things under control.
If you have players who can only post one time a day and they come home after a long day of work and see a wall of text...well, that can be hard to wade through. Not to mention hard for the GM!
On the flip side, expect posting rates to slow down during holidays, summer vacation, when kids go back to school, etc. This is where communication comes into play again.
10. Posting Rates.
Establish a posting rate for your game and stick with it. I usually set my posting rate at one post every 1-2 days, with the realization that real life is occasionally going to slow that pace down. Again, communication. Put your expectations up front and hold your players and yourself to it. If someone is going to be sidelined for a bit, it takes almost no time for them to send a quick out-of-character message stating as such. The last thing you want to happen is to be waiting around for someone to post.
My general rule of thumb is I look to remove players from the game after two weeks of no communication. If a player has been in the game for a while and is typically a reliable poster, I will sometimes wait around longer for them to resurface.
But at some point, as a GM, you need to either remove the player or step-in and NPC their character so the game can move on. Not doing one of these two things will derail your game and put it on the fast track to fading to oblivion.
At any rate, hope this helps. PbP can be a lot of fun, but it is also a lot of work. Very rewarding work though.