Someone asked me for this after my last posting, so I’ll just list a few places here where I’ve previously played online.
Most of my IRC gaming I’ve done on the network Otherworlders.org. There are a few channels, such as EN World’s official channel #dnd3e, which I moderate, and #realmsofevil, where one can hope to find an online game. They will be mostly D&D, though I am aware of at least one user running Shadowrun.
Both network homepages have guides on how to use IRC, if you’re new to it.
OpenRPG, as I stated, I use solely for playing Living Greyhawk. For organising games, there are two Yahoogroups, LG Europe Online and Online Game Day. The activity has dropped since the announcement of the campaign’s ending, though. Many games are also organised via Warhorn.net’s Adhoc Online Gameday event site. Most of the games take place on the Blackstar server, and in the evenings it can pay off to just go sit there in the lobby and see if a game forms.
Though I don’t do these myself, I can recommend EN World’s and RPG.net’s forums for those who like this kind of thing. Most every gaming forum has a place for these, though. Some of them are active. Others are not. Roolipelaaja’s play-by-post forum hasn’t had a single post, ever.
Finally, there are MUDs, a dying breed of games. Mudconnector, I suppose, is as good a place as any to get started. To play a MUD, you’ll need a MUD client program. ZMud is what I used, but I can’t seem to find a free client there now. For the MUDs themselves… well, FaerunMUD is gone, but Arantha and Rauvyon persist. Tell them Dyvnal sent you, for some blank stares. There’s also Aardwolf, but that’s about as much a roleplaying game as World of Warcraft is. Then there’s also BatMUD, which I’m not personally familiar with but is positively ancient and still going strong, which must count for something. It’s of Finnish make, but the language in the game is English.
And then there’s always World of Warcraft. I’m on Scarshield Legion as Kronth the tauren druid and on Dunemaul as Arrindor the blood elf warlock. You’re unlikely to ever be able to catch me there, though, since the damn thing keeps crashing my computer.