Read carefully.
Uller said:
So now we have two answers...which is it. I'm inclined to agree with this one as I can't find a reference in my PsiHB or the SRD's Psionic Powers on aiming targeted powers so I think the targetting spells applies(since psionics are spell-like abilities).
No. Look over what was written very carefully; this is one answer, made in two parts. There are two different kinds of spells: target-specific (such as charm person) and area (such as fireball). Both are treated differently.
"You need to
see your target to manifest
targeted powers (like inflict pain) or spells (like hold person)." (Bold added for emphasis.) In order to cast a target-specific spell (or manifest a target-specific power), you
must be able to discern your target in some way, shape, or form. If a target is invisible and cannot be otherwise pinpointed, target-specific spells and powers cannot be used against it. A target-specific spell or power is any spell or power which has a "target" in its descriptive text rather than an "area".
"Yo need to
define an area for
area of effect powers (like mass concussion) or spells (like fireball). " (Again, bold added for emphasis.) In order to cast an area spell (or manifest an area power), you
must define the area of effect in terms which you can discern in some way, shape, or form. You cannot say "I cast fireball in the area where invisible stalker is hiding" if you do not know the location of the invisible stalker (though you can always guess and try based off of your assumptions). Though you can use area effects blindly,
you must determine where these area effects land yourself, in terms which you can identify. An area spell or power is any spell or power which has an "area" in it's descriptive text rather than a "target". (An exception to this rule is mindfog, as the writters of the PHB appearently accidently wrote "effect" instead of "area", when the spell quite clearly effects an area.)
Occassionally, a spell (such as dispel magic) can be used as a target-specific spell OR an area spell; the caster must determine in which manner the spell will be used when he starts casting the spell, and then the spell will become either a target-specific spell or an area spell.
The long and short of it is that psionic powers work almost exactly like spells (except one is called powers and the other is called spells). A slap on the wrist for the psionicist for taking advantage of the incompetent DM, and a slap on the wrist for the incompetent DM for being so incompetent.