Hussar
Legend
Yup, the biggest competitor for D&D is.... D&D. 
But, rolling back to the original point of this thread, I'm going to cross post quote something from another thread:
It's from the rather long http://www.enworld.org/forum/new-horizons-upcoming-edition-d-d/ thread.
I think this is precisely what I'm talking about. Before 3e, it was pretty much presumed that the DM was going to make stuff up like this. You didn't wait until the gunslinger class was released, you did it yourself.
Heck, back in 1e I DID do this myself. One of my players was a huge Steven King fan, and when The Dark Tower series started, begged me to play a gunslinger. Thus, a ranger class (this would be 2e by then - around 1990 or so) got guns. Done. We didn't even consider having to wait for TSR to get around to this.
But, I think that sort of approach has really changed with 3e. Now we want everything to be "official" because house rule and home brew have garnered such negative connotations. The idea that you just do it yourself has really fallen by the wayside for some groups. I think anyway.

But, rolling back to the original point of this thread, I'm going to cross post quote something from another thread:
To be perfectly honest, I don't like free form mechanics. I like to build with in the confines of the rules when it comes to NPCs and monsters. I don't like to "just make it happen" unless it is with regards to fluff. Can I say Gunslingers exist in 4th edition? Sure I can but I don't like that. I want the mechanics for a Gunslinger to be present so I build off of that.
It's from the rather long http://www.enworld.org/forum/new-horizons-upcoming-edition-d-d/ thread.
I think this is precisely what I'm talking about. Before 3e, it was pretty much presumed that the DM was going to make stuff up like this. You didn't wait until the gunslinger class was released, you did it yourself.
Heck, back in 1e I DID do this myself. One of my players was a huge Steven King fan, and when The Dark Tower series started, begged me to play a gunslinger. Thus, a ranger class (this would be 2e by then - around 1990 or so) got guns. Done. We didn't even consider having to wait for TSR to get around to this.
But, I think that sort of approach has really changed with 3e. Now we want everything to be "official" because house rule and home brew have garnered such negative connotations. The idea that you just do it yourself has really fallen by the wayside for some groups. I think anyway.