Hello ciuly,
Interestingly enough, when Microsoft launched the Exchange Chat Service (an IRCX server), they implimented commands which could let you exchange other interesting data that would not necessarily interfere with the normal operations of the channel. Particularly, it was geared for those who used to use Microsoft Chat (it had the comics) and Microsoft VChat. However, the protocol itself was designed rather well and is versatile yet today.
At one point in time, before mIRC (around version 5.92?) supported the IRCX protocol, an individual wrote a chat client called "TurboIRC". TurboIRC supported (and was geared for) IRCX and it even came with a chess game and also services that you could purchase if you ran an IRCX network. I think TurboIRC is still available today and I know that you can freely download the Microsoft Exchange Chat Service from Microsoft's site... but it has to be run on NT Server 4.0, 2000 Server, or 2003 Server. It will not run on NT Workstation, 2000 Professional, or XP Home/Professional.
mIRC now supports IRCX and can be setup to impliment gaming features... it's been done before.
If you're interested in more information, send me a private message.
Regards,
John