It's on-topic so long as the problem is tied to gaming.
As a rule of thumb, if you can remove every mention of games or gaming from the question and have it still fully describe your problem, then it's probably off-topic here and better asked at SuperUser. If removing those mentions from the question fundamentally changes the problem it describes though, this is probably the right place to ask. Your Quake 3 example seems to pass that rule of thumb, and the Path of Exile example definitely does.
A small (and somewhat debated) exception is for software that is designed primarily for gaming use: that's currently considered almost always on-topic here, because problems with software that is primarily designed for and used by gamers for gaming is almost always about (wait for it...) gaming. For stuff like that, our current consensus is that it's generally on-topic without needing to mention a specific game.