For houserules and summaries of 13th Age things that not everyone is familiar with yet. Any races or classes with immediate effects are probably going to need houseruling, if only because play-by-post doesn't really allow for instantaneous back and forth.
Having played in hvg3akaek's Crown of the Lich King, I've gotten used to several of his houserules which have smoothed out the play of 13th Age on the forum. I feel no shame pilfering from a wiser and more experienced GM.
A big part of this game is the fact that players have a whole lot of narrative control. I don't want to hear things like 'can I do this?' Assume the answer to be "yes", and explain why this makes sense for your character in your post! Make it interesting and I'll be on board. If you can work a way to cross that river using your intelligence and your background in doughnut baking, then explain how in your post, make it interesting, and roll up those dice.
If you are in a dedicated subforum for your game, you may have a game-specific houserules thread.
Please see your game forum for any additional rules not detailed here:
Dread Moon Rising • Ill-Met by Gloomlight
Rule zero applies. Translation: GM's word is law. Tell me if you don't think something is fair, but I'll make the final call. Disagreements do arise from time to time, but I think I'm a fairly open and easy-going GM. (I could be delusional, of course.)
Metagaming strongly discouraged. Obviously there is a certain amount of "table talk" that players can and will indulge in, but I won't allow you to start debating your plan of action to maximize your effectiveness... in the real world, you don't have time to decide if you will attack or not, you just do it. I'll give you a heads up if I think you're pushing it.
Please play your characters as you've built them. (This sounds obvious, I know.) This means that if you chose a lawful character and decide to go on a crime spree, there are going to be penalties. This applies to Icon Relationships as well as quirks, talents, or items, whether it's written on the character sheet or not. If you play your character in a way contrary to how you laid out the character, I'm going to call you on it. Can you change alignment? Of course. Will there be some kind of plot twist in response? Definitely.
Please spread RPXP around. We all like being told our post made someone laugh, and that means me (the GM) too. This site also runs a post of the month contest, and I encourage you to nominate each other. This game should be a great group of players, and it would make me really happy to see you all boosting each other up. While I would be flattered if you wanted to nominate me for Post of the Month, as one of the judges, I don't qualify. But you all do!
Posting twice a week is a fair speed to keep things moving without hurting any of us. Please stick to this, and I encourage you to post more than I do. Just because I move the plot along twice a week doesn't mean two of you can't get in an argument and post ten times between my posts. If you miss one here and there, that's okay, I will prompt in the OOC thread if more than half of you haven't updated by the time I'm ready to post.
We all have lives, which do come first, but please try to warn us of absences. (That goes for my sporadic week-long migraines, too.) There's an Oath of Sangus going around, which I heartily agree with. It simply points out that as responsible players, we can find three minutes to post in an OOC thread. I post absences in my signature as well, and I will check yours if that is your preferred method.