I put this idea forward as an example in the "What Class Would You Add" thread. The thread got me thinking on how I'd actually work it up and the following is a basic idea I came up with.
Concept: a Moderate Divine caster (Bard-like spell progression), that is trained to fight supernatural threats (one foe in particular) with knowledge. Keep in mind, this is only a basic framework. It doesn't even have a complete order discription as an example.
L Class Features
1 Order, Sense Weakness +1, Spellcasting, Grimorie
2 Ancient Lore: Sense Unnatural
3 Sense Weakness +2
4 Order Secret
5 Sense Weakness +3, Requisition: Talisman
6 Ancient Lore:
7 Sense Weakness +4
8 Order Secret
9 Sense Weakness +5
10 Ancient Lore:
11 Sense Weakness +6, Requisition: Relic
12 Order Secret
13 Sense Weakness +7
14 Ancient Lore:
15 Sense Weakness +8
16 Order Secret
17 Sense Weakness +9, Requisition: Artifact
18 Ancient Lore:
19 Sense Weakness +10
20 Order Secret
HD: d8
SP: Int + 6
Skills: Appraise, Bluff, Craft, Diplomacy, Heal, Intimidate, Knowledge (All), Linguistics, Perception, Perform, Profession, Ride, Sense Motive, Spellcraft, Swim, Use Magic Device. An Inquisitor also gets class skills listed under her Order in "Training"
Proficiencies: All Simple Weapons and the Symbolic Weapon of her Order. She is also Proficient in Light Armor and Shields.
Order: At 1st level an Inquisitor selects an Order to belong to. This gives the Inquisitor a particular Foe she specializes in, two additional class skills listed under "Training". A +2 Bonus to the Knowledges listed as "Primary Knowledges" which increases to +4 if she gains 10 ranks in one, and a Martial Weapon Proficiency under Symbolic Weapon.
Sense Weakness: Inquisitors train constantly in their battles against there foes and develop an uncanny knack for spotting supernatural entities vulnerabilities. At 1st level, and every other level there after, an Inquisitor gains +1 damage to her damage roles solely for the purposes of defeating Damage Reduction. This damage is doubled when fighting her Order’s foe and is treated as regular damage in all respect, even applying to her Order’s foes that do not have DR. Sense Weakness does not work against natural creatures, Humanoids, Beasts, Plants, and Oozes that are immune to its effects, unless otherwise stated.
Spellcasting: Gets access to 1-6 levels of Divine Casting, with Int the primary stat. Suffers Spell Failure as a drawback to hopefully balance it. Gets Orisons too.
Grimorie: Like a spellbook.
Ancient Lore: Equal to Int + 1/2 Inquistor Levels. Allows you to activate abilities like Sense Unnatural. This works like a detection spell that lasts 1 minute/level. 1st Round it detects a supernatural creature in the area of effect(No Humanoids, Beasts, Plants or Oozes). 2nd it lets you zero in on specific ones and gives you a general power level. 3rd it gives you the type.
Order Secrets: You gain the Secret listed for your Order at that level.
Example Order:
The Order Stalwart: These Orders have dedicated themselves to stopping the enemies of life. They fight an unending battle against the undead. When one threat ends they move one to the next. The Inquisitors of these orders are perhaps the most free with the knowledge they possess then any others. They constantly preach how to detect, ward against and destroy the Undead to any one who will listen. There is no threat more implacable and these men and women will fight it to the bitter end.
Primary Knowledge: Knowledge History and Knowledge Religion.
Training: Climb and Survival. Orders Stalwart often travel where mortals fear to tread.
Foe: Undead.
Symbolic Weapon: Flail
Secrets: Channel Positive Energy (SU): When the Inquisitor reaches 4th Level, she gains the supernatural ability to channel positive energy like a Cleric. Using this ability consumes two uses of her Ancient Lore ability. An Inquisitor uses her level as her effective Cleric level when channeling positive energy. This is a Charisma-based ability. The Inquisitor always channels positive energy regardless of her alignment.
Detect Undead (SP): When the Inquisitor reaches 8th Level she may spend an Ancient Lore point to cast Detect Undead as a Spell-like ability. The caster level of this effect is equal to the Inquisitor’s level. This is a Charisma-based ability.
Shield of Life (EX): When an Inquisitor reaches 12th Level she becomes immune to being raised as Undead or being turned into a spawn. She also gains a bonus to her saves versus Death effects, Negative Energy effects, and all Supernatural and Spell-like Abilities of Undead equal to her Charisma.