Proficiency, Spell Penetration, and Lore Items

[ivarthevic]

Edited - thanks for the comments.

Do I have any of this wrong?

What items should I equip for which spells?

Scorching Ray and Wall of Fire - Potency and fire lore item set.
Magic Missiles - Potency and kinetic item set.
Web - Conjuration item.
Phantasmal Killer - Illusion and spell penetration item set.
Hypnotism - Enchantment and spell penetration item set.
Ray of Exhaustion - Necromancy and spell penetration item set.
Cone of Cold - Potency, ice lore, and evocation items.

Understanding item effects

Potency items increase the damage of the spell. There are two types of potency items: general potency items and items that increase the damage of specific spell types (e.g., combustion items increase the damage of fire spells only).

Spell penetration (SP) items help overcome spell resistance on the basis of the formula: 1d20 + your caster level + any feat, enhancement and item modifiers => character spell resistance.

Spell difficulty class (DC) modification items help overcome the saves against the spell using the formula: [10 + Spell Level + CHA mod + feats + items] => d20 + character’s reflex, fortitude, or will resistance. As can be seen, the Heighten Spell feat increases the effectiveness of spells with a save check.

Spells that benefit from potency and lore items

Spells that have no spell resistance check (i.e., that do not benefit from a spell penetration item) and no save check (i.e., do not benefit from a DC modifier) include: fire wall, magic missile, force missiles, solid fog, acid fog, globe and lesser globe of invulnerability, acid rain, scorching and polar rays, and obscuring mist.

Spells that would benefit from potency, lore, and DC modification items

Damage spells that have no spell resistance check but do have a save check include: Cone of cold (Evocation school spell with Reflex save).

Spells that would benefit from DC modification items only

Crowd control spells that have no spell resistance check but do have a save calculation include: Web (Conjuration school spell with Reflex and Strength saves).

Spells that would benefit from spell penetration and DC modification items

Spells that have both spell resistance and save checks include: Phantasmal Killer (an Illusion school spell with a Fortitude save), Hypnotism (an Enchantment school spell with a Will save), and Ray of Exhaustion (a Necromancy school spell with fortitude save).