Casting the "Nightmare" spell.

[iosifs]

As a DM, I have an antagonist that "haunts" the PC with the lowest will-saving roll with the spell, sometimes inflicting damage. However, I kind of want to be cleared up on the use of this spell, or magic in general as I don't have many magic-users in my players' party, as well the main "magic users" are the antagonist and another (for now / so far).

I'm a rather new DM and want to understand spell-casting as clearly as I can without getting confused with googling and flipping through all my books.

Questions I need answered, basically...

1. Are direct magic attacks/spells counted as range (& is DEX mod added to attack or damage, both)?
2. Are instantaneous spells such as Nightmare, that have no range, etc, required to be rolled for their success or are only based on the target's will-saving roll?
3. Are Connection and Knowledge added against one another since it's target vs. caster?

[The Sideromancer]

1/2. Spells will call out attack roll if it is used. These are computed like other attack rolls of the type (Dex for ranged, str for melee by default). If nothing resembling "Make a [ranged/melee] [touch] attack" is mentioned, success is likely to be determined only by whether the target saves.
3. What is connection? Can you cite where you found it?

[blahpers]

1. If the spell requires an attack roll, such as shocking grasp or scorching ray, those would apply the caster's Dexterity modifier to the attack roll (but not the damage roll). The damage from nightmare isn't the result of an attack*--in this instance meaning "that thing you do that requires an attack roll"--so there's no modification to attack or damage. You cast the spell, they roll their saving throw, and if they fail they take damage and the rest of the effects.
2. If the spell requires an attack roll, it will say so in its description. Otherwise, the only defenses are saving throws, spell resistance, or anything in the spell description that would cause the spell to fail. In the case of nightmare, the victim gets a saving throw (and spell resistance applies, if any); also, it only works on sleeping victims, so the caster must wait until the victim is asleep before completing the spell. (Plus, creatures who don't sleep are immune, per the description.)
3. Yes. A lock of hair is sufficient to cancel out the penalty for having no knowledge of the victim, leaving the saving throw at no bonus or penalty. If you're casting it on your best friend using a lock of their hair, your friend will be hard pressed to make the saving throw with a -15 penalty. (Some friend you are!)

* Note: This word is heavily overloaded in Pathfinder, thus causing 20%** of all rules questions.
** I just made that number up.