It may seem like an odd platform and there are indeed limitations.
As you play, use your imagination and see your twitter account as a real character you're playing as if it's a play. What are their motivations? What would they do in this circumstance? Or, just hack stuff and take their treasure.
You will run into things where hack and slash will get you all killed, but it would be a glorious defeat, or at least somewhat memorable....
Whenever you do a die roll on Twitter, some conventions will help keep things neat. Many times you just describe what your character does, but when a roll is called for it works like this:
Smidgeodice will send the roll back to you and to the GM. Instructions will follow, like "You missed." or "You hit, roll 1d4 damage." or "Critical! Roll 1d10 on the critical hit chart!" or etc.
It is assumed that everything you tweet is "in character" so when you want to communicate with the players or GM (GameMaster) out of character box in your message with OOC like this:
I look for secret doors @smidgeodice 1d6 [OOC How do we go about using abilities that are always on?]
The whole message can be OOC if you want like:
[OOC Can I bring a spell online prior to entering the room and hold it until I want to release it?]
Again, once the game starts, try to use OOC when not speaking or acting in-character. It just helps clarify things. It's noit a hard and fast rule and no one gets kicked out for doing it wrong, it simply helps. You can always message the GM directly (and secretly) inside twitter using Direct Message. Stealing from your comrades, use DM!
Actions and messages need to be kept short. Being forced to be concise is one of the gems in Twitter. However, this causes the GMs descriptions to be shorter than in a real life game. Don't be afraid to ask questions before acting.
You are free to map and be a cartographer as you wish. I may post maps here and there, but I'll lean on descriptions and see how it goes.
Some, if not all of us know each other in real life. Feel free to communicate however you wish outside the game but try to keep gameplay in Twitter. eg. Don't make a habit of BBMing the GM instead of DMing him in Twitter. This is solely to help us see how to best use Twitter for the game and to keep it a fair playing field if people we don't know so well start to play with us. If we come upon some irritating limitations when we have access to better software or easy additional software, we'll look at using it. Realistically, BBM might be a better medium, but this is what we've started to try so we'll see where it leads.
The intro adventure is a little open, but to keep things simple, I may try to utilize dungeon crawls as much as possible.