I miss Assassin spells, and I'm passing fond of the old Factotum class. (As evinced by my attempts at a Factotum Rogue archetype.) So I had the idea that maybe the Rogue and Ninja could-- at the expense of talents-- be upgraded to half-casters.
So here's what I'm thinking:
- Paladins and Rangers get Orisons at 2nd level, adding the 0th level spells from the Cleric and Druid spell lists, respectively, to their class spell lists. They can prepare 3 Orisons per day.
- Remove the Minor Magic and Major Magic Rogue talents.
- Rogues and Ninjas may select Rogue/Ninja Magic as a Talent/Trick, with Int/Cha 10 and 2nd level as prerequisites, granting them 3 cantrips known to be selected from any arcane caster list.
- At 4th level, Rogues and Ninjas with Rogue/Ninja Magic may select Advanced Magic as a Talent/Trick, granting them an extra cantrip known, 0 1st level spells per day, and 1 1st level spell known from any arcane base class spellcasting list or the Assassin list.
- At 8th level and every 4th level thereafter, Rogues and Ninjas may select Advanced Magic again, granting them 0 spells per day and 1 spell known for the next spell level, and 1 additional spell per day and spell known for each lower level.
- Rogues and Ninjas can gain an additional spell per day or spell known, of up to the highest level they can cast, as a Talent they may select multiple times.
- Rogues with Cantrips and Advanced Magic treat Intelligence as their spellcasting ability; Ninjas use Charisma instead. Their caster level is equal to their class level -3. Both classes may cast Rogue/Ninja spells in light armor without ASF.
With some adaptation, this could be replaced with Divine Magic, or folded into a ki point system like the Qinggong Monk or Ninja.