From the introduction:
This is a game for you and your friends to play over social media. You play it on your phone or from your computer via texts or another messaging service. People can drop in and out of the game at any time. You might want to make a public group for the game on Facebook, Google or something like that which will allow anyone playing to post and read each other's posts. If you can turn on time stamps, so each message shows when it was originally sent, do that.
Whenever you start a new game you should post a link to these rules at the beginning so anyone who finds it knows it's just a game, and can join in if they like.
Game play consists of writing messages to the other players from the perspective of your character. You'll want it to read and feel like a real conversation. If your character is getting chased by guard dogs, say something like, "I hear barking. I think they have bloodhounds. I'm heading for the river" Then later if things get worse you might say, "One of them near took my leg off!!! That's a lot of blood :(" Definitely use emojis, expressive gifs, obscure acronyms, and anything else you might commonly see in text based conversation.