Comments from the Finger: One of the more powerful prestige classes for rogues in 3.5, the Daggerspell Mage was a combination of spells, flurries of attacks, and sneak attack damage. Hopefully, this fits nicely in the damage curve while keeping the charm of the original.
A master of blending the carnage of twin daggers with arcane spellcasting, daggerspell mages make devastating foes. To learn and perfect the art of balancing a spell on the edge of a blade takes years and must be practiced meticulously, but rewards it’s students with exceptional power.
When you reach 3rd level, you gain the ability to cast spells. See chapter 10 for the general rules of spellcasting and chapter 11 for the wizard spell list.
Cantrips. You learn two cantrips: true strike and one cantrip of your choice from the wizard spell list. You learn another wizard cantrip of your choice at 10th level.
Spell Slots. The Arcane Trickster Spellcasting table shows how many spell slots you have to cast your spells of 1st level and higher. To cast one of these spells, you must expend a slot of the spell's level or higher. You regain all expended spell slots when you finish a long rest.
Spells Known of 1st-Level and Higher. You know three 1st-level wizard spells of your choice, two of which you must choose from the evocation and transmutation spells on the wizard spell list. The Spells Known column of the Arcane Trickster Spellcasting table shows when you learn more wizard spells of 1st level or higher. Each of these spells must be an evocation or transmutation spell of your choice, and must be of a level for which you have spell slots. For instance, when you reach 7th level in this class, you can learn one new spell of 1st or 2nd level. The spells you learn at 8th, 14th, and 20th level can come from any school of magic. Whenever you gain a level in this class, you can replace one of the wizard spells you know with another spell of your choice from the wizard spell list. The new spell must be of a level for which you have spell slots, and it must be an evocation or transmutation spell, unless you’re replacing the spell you gained at 8th, 14th, or 20th level.
Spellcasting Ability. Intelligence is your spellcasting ability for your wizard spells, since you learn your spells through dedicated study and memorization. You use your Intelligence whenever a spell refers to your spellcasting ability. In addition, you use your Intelligence modifier when setting the saving throw DC for a wizard spell you cast and when making an attack roll with one.
Spell save DC = 8 + your proficiency bonus + your Intelligence modifier.
Spell attack modifier = your proficiency bonus + your Intelligence modifier.
At 3rd level, you can imbue your daggers with magical energies. As a bonus action you may imbue a dagger you are holding with a spell you know of first level or higher, expending a spell slot and spell components as though you cast the spell normally. You may only imbue spells with a duration of instantaneous. This dagger remains imbued so long as you maintain concentration on it.
When making an attack with an imbued dagger, treat it as a normal attack. If the attack successfully hits a creature, the spell is cast centered on your target or targeting only the creature hit by the dagger, as appropriate. Spells requiring spell attacks automatically hit, since the dagger has already struck the target. Line and cone spells are cast in the direction of the attack.
When using an imbued dagger to make a Sneak Attack, you may only apply half the number of d6 listed on the Sneak Attack table, rounded down, to the attack.
At 9th level, you can use your daggers to scale sheer walls. Climbing no longer costs you extra movement, and you may climb on any surface regardless of whether or not it has handholds if your daggers can penetrate its surface. Additionally, you require no ability check to climb a surface at half your movement speed.
At 13th level, you can harmlessly absorb your daggers (even if they are poisoned) into your arms as an action. The concealed dagger cannot be detected even with a careful search (though it does radiate a transmutation aura under detect magic) and does not restrict your movement in any way. You may produce these daggers as a part of the Attack action.
Greater Imbue Dagger
At 17th level, you may now imbue two held daggers instead of one as a bonus action, expending spell slots for each separately, and concentrate on two imbued daggers at once.