There are definitely rails, but maybe less so in this thread than others. ”Do not derail threads.” as it says in the Forum Guidelines.
I may as well give my own evaluation on each board's railing to clarify what I said.
General Discussion has very few rails, probably the fewest for a single board in Bay12. I've made a thread or two in GD, that shit derailed
so fast (I'm not pissed about that, I think it's just funny). Rails are an illusion, for the most part. The emotion threads are especially susceptible, since they don't have an well-defined topic beyond a particular emotion. Just don't upset Toady.
Life Advice and Creative Projects are not well-known for derailing (though the Random art thread does a little bit of drifting from time to time). I don't think I've seen a single total derail in those boards yet. Minor drifts, maybe. I've certainly never seen the Generic Computer Advice Thread turn into a cooking discussion, that's for sure.
FG&RP, from what I've seen, is variable. Minimalist games, less serious games, those will derail very quickly (can they be said to have rails?), but the more serious ones generally only derail once in their entire lifetime, if that. Ones that are played by association (Corrupt a wish, Word association game, Rate ____), those have almost no rails. The rails appear and disappear at the drop of a hat.
The middle boards (Other Games, Curses)... I'm not too familiar with. Derails not particularly often, but Other Games tend to do it more often than Curses. Might just be a size thing, though.
The upper boards tend to be quite rigid as far as rails go. It's expected that you
don't try derailing the thread you're on (though CG&S is less strict about this), lest you incur the wrath of The Toad. People will call you out if you try.
I think the general trend is that "serious" threads tend to derail less than "non-serious" ones. Seriousity isn't an absolute measure here; it's relative to its parent board. Ameripol derails more than Future of the Fortress, for instance, despite both being serious.