Spell penetration

Spell Penetration check
Spell Resistance (SR) is a special anti-spell defense possessed by some creatures. Spell Resistance is an additional layer of defense against most non-damaging magical attacks, in that it adds an extra roll that the caster has to make for his magic to "land" on that target.

Spell Resistance only matters if the spell's creature actually has it, and the spell being cast is one that can be stopped by Spell Resistance. In DDO, spells that most purely cause damage ignore Spell Resistance.

Spell Penetration is the act of trying to penetrate that defense. Spell penetration roll is a caster level check, i.e. you roll 1d20 + caster level. This roll is modified by additional bonuses listed below.

Spell Penetration feats

 * Spell Penetration feat gives +2 to die roll
 * Greater Spell Penetration feat gives another +2 to die roll
 * Epic Spell Penetration feat gives another +4 to die roll
 * Past Life: Wizard grants +2 to the die roll, it can be acquired up to 3 times for a maximum of +6
 * Past Life: Favored Soul grants +1 to the die roll, it can be acquired up to 3 times for a maximum of +3

Spell Penetration enhancements

 * Spell Penetration class enhancements gives +1, +2 or +3 to die roll
 * Epic Destiny Abilities can also grant up to +3
 * Elves and Sun Elves can get up to +3 in racial enhancements with the Arcanum enhancement

Item enchantments
The Spell Penetration item enchantment gives an equipment bonus to spell penetration checks. Notable sources:
 * Named items - +1 to +6
 * Randomly generated caster weapons: +1 to +5
 * Crafted Thunder-Forged items: +7 (Tier 2 upgrade)


 * (Previously, an item's Spell Penetration bonus applied only for spells up to a given level, for instance a Spell Penetration III Dagger would give a +2 bonus for spells of the levels 1, 2, and 3. Items with these enchantments have been retroactively converted to new format.)

The Arcane Augmentation item enchantment increases your caster level directly and thus increases your spell penetration checks.

Maximum spell penetration
Breakdown as of Update 28:

Wizard
 * 20 Levels

Enhancements
 * 3 Sun-Elf (Arcanum)
 * 3 Archmage (Spell Penetration) Note: Bards get 5 from Spellsinger Tree

Items
 * 7 Thunder-Forged Tier 2
 * 2 Insightful Bonus (Item:Epic Increased Potential)
 * 2 Spell Augmentation (Item:Gauntlets of the Arcane Soldier)

Epic Destiny Abilities and Twists
 * 5 Epic Destiny Caster Levels
 * 3 Piercing Spellcraft (Magister)
 * 3 Piercing Spellcraft (Exalted Angel)
 * 2 Echoes of Ancestor: Wizard

Feats
 * 2 Spell Penetration
 * 2 Greater Spell Penetration
 * 4 Epic Spell Penetration
 * 58 Spell Penetration before Past Life Feats (60 if Spellsinger)

Past Life Feats 
 * 6 Wizard Past Lives
 * 3 Favored Soul Past Lives
 * 67 Spell Penetration with Past Life Feats (69 if Spellsinger)