Pielorinho
Iron Fist of Pelor
Encounters with dragons? Not so much of a problem: dragons have blindsense, meaning they can pinpoint an enemy within 60' (although the enemy still has total concealment). Breath weapons aren't subject to miss chances.
One possible houserule that I'd suggest is that when you're grappling with an invisible opponent, you're not subject to miss chances, even if you use light weapons to attack. This seems like a pretty natural idea to me.
Monsters facing invisible creatures ought to ready an action, to attack the source of any evidence of the invisible creature. This evidence can take the form of a fireball bead's source, an arrow's source, or even the source of the chanting noise (although this requires a listen check).
Finally, you can let smarter monsters be creative. They might spin a rope around their head, gaining a touch attack (with no miss chance) on anyone within 15' or so; if they succeed at the touch attack, the rope bends around the invisible character, momentarily revealing the square they're in. They might throw a handful of dust in an arc similar to that of the burning hands spell, similarly revealing the location of an invisible opponent for one round (not by dust adhering to the opponent, but by the absence of dust in one square). A wineskin opened and spewed around might have a similar effect.
Don't use such tricks all the time, but occasional use of them can keep encounters fresh and exciting.
Daniel
One possible houserule that I'd suggest is that when you're grappling with an invisible opponent, you're not subject to miss chances, even if you use light weapons to attack. This seems like a pretty natural idea to me.
Monsters facing invisible creatures ought to ready an action, to attack the source of any evidence of the invisible creature. This evidence can take the form of a fireball bead's source, an arrow's source, or even the source of the chanting noise (although this requires a listen check).
Finally, you can let smarter monsters be creative. They might spin a rope around their head, gaining a touch attack (with no miss chance) on anyone within 15' or so; if they succeed at the touch attack, the rope bends around the invisible character, momentarily revealing the square they're in. They might throw a handful of dust in an arc similar to that of the burning hands spell, similarly revealing the location of an invisible opponent for one round (not by dust adhering to the opponent, but by the absence of dust in one square). A wineskin opened and spewed around might have a similar effect.
Don't use such tricks all the time, but occasional use of them can keep encounters fresh and exciting.
Daniel