Lately I've been doing a lot of gaming online, via chat rooms -- with a regular group and a regular time for a session each week, just through text rather than in person or via Skype or something. This has some procedural differences and a different feel and focus from either tabletop or other kinds of online gaming. While I have a fairly good idea of what kinds of systems "work well" in this environment (in particular, systems without a whole lot of procedural steps back and forth between the GM and player, or player-to-player), everything I've used in this kind of gaming was intended for tabletop play first, and adapted to a greater or lesser extent to the online environment. Are there any systems out there that were specifically designed for use with online chat, or that mention online real-time text as a way to play in the rulebook or supplementary materials?
The only one I'm aware of is Goldleaf Games' Code of Unaris.
There is indeed, Code of Unaris, which was developed for online play.
Following that, what you're looking for are the following traits:
- Low GM dice involvement.
- Quick/obvious results based on rolls.
- Less negotiation over roll results.
1 means you don't want to be playing D&D generally. The players don't need to sit there and wait for the DM to roll dice and let them know if they get hit - the players want to be engaged. Something like Cinematic Unisystem (Buffy, Angel) is good because the DM has fixed-stat characters, and players either try to hit that value on an attack, or defend against that value on defense.
2 means that you don't want to have a lot of rolling going on. Player rolls attack then DM rolls defense then Player rolls damage and DM rolls soak is killing in a text-only game. You want the player to roll once, or if they have to roll twice, have them make both rolls at the same time and then work it out. Something like Unknown Armies where the roll is both the attack and the damage is great for this.
3 means that you don't want people having to negotiate a failure or a success. I'm in a FATE game online right now, and it's a real problem when a player rolls a die, and then the DM says you don't succeed, and then the player needs to figure out if he wants to spend any FATE points. It turns a quick roll into a slow grind.
So, at the end of it all, I suggest the Buffy/Angel RPGs, although it's a shame that they're not really available right now. Outside of that, feel free to do a little system hacking - D20 had a variant in the Unearthed Arcana supplement where players do all of the rolling, and I would suggest using that if you're going to try D&D 3.x/Pathfinder online, although I will note that the lack of positioning is a bit of a pain as well.
Warriors Adventure Game was specifically designed for online play, although not necessarily for real time (although since it also works at a table, you could assume that it handles real time as well as time-delayed).
CORPS (by BTRC) has been touted by its designer as good for play by post and play by chat, due to much reduced dice use. I've seen it used for play by post on some early internet BBSs.
The now out of print Theatrix (by Backstage Press) was touted by its fan base as suitable for online play modes. Since it uses no tokens nor randomizers, it's actually quite suitable, but the lack of randomness can be an issue for some. I believe there is a yahoo group dedicated to it.
While arguable as to being Roleplaying, En Garde! was originally designed to be played both face to face and play-by-mail. Last I checked, buying a copy entitled one to post houseruled versions for one's players... And lots of houseruled versions exist online. Originally published in 1975 by GDW...
Key-RP claims to be specifically designed for this kind of stuff.
Freestyle is "a diceless system created for online RPGs". If you want, another setting can be adapted.
It appears to be the first version of an unfinished system as of 3/6/4.
Vincent Baker's new game, The Doomed Pilgrim “is designed for online play. You play the pilgrim, and your friends on the internet try to see you to your doom.” If I'm remembering correctly, you don't need live text chat to play; a forum thread or G+ comments work just as well or better.