The question that triggered this for me was: is there a class/achetype/pestige class/feat that can absorb the lifeforce of its ennemy to fuel it's power ?
Sometimes a querent wants to know how to do X thing in Y system. That's usually fine; there's often not more than three or four ways to do a single thing in even 3.X-level-complicated systems. Sometimes, though, there are a LOT of ways to do something, and without more direction as to what makes one way better than another for the querent, it seems like the question could be Too Broad.
It's often not possible for a querent to realize how broad what they are asking about is, though, without the same knowledge they'd need to answer their own question. For example, there are a LOT of ways to get past a door in 3.x (though not so many that asking how to do so would actually be Too Broad, I think), and it's unreasonable to expect a querent to necessarily realize that. Even if we scope down to just beating a door open via violence, there're still two entirely decoupled ways to handle that mechanically.
How broad is Too Broad with questions like these, and how should we handle them when they show up?