This covers a frequent group of separate but connected questions that I receive. It is a bit lengthy, but it consists of a number of examples for clarity.
Let's start with the rules themselves located in the Prime 5.1 supplement:
Non-Player Character Limitations (1.8)
The creation process of Non-Player Characters is limited in the same manner as Player Characters, except experience points may be added to reflect the length of the chronicle. The type is still subject to the Storyteller approval levels, but is one level lower than indicated on the venue chart. Venue-specific antagonist, such as Fomori for Garou or Autumn People for Changeling, are allowed with Low Approval, except for those eligible as Player Characters in other venues, which require Mid Approval. Players may only play Non-Player Characters whose Power Class is available as a Player Character based upon either the Players Member Class, or the Member Class of the Storyteller sponsoring the Non-Player Character. Any of these restrictions may be superseded with High Approval.
Each of these statements is simple, but each builds on the last, giving results that may be missed on a quick read-through. Let's take each of them in order and see how they apply and build.
"The creation process of Non-Player Characters is limited in the same manner as Player Characters,"
This means that a NPC is handled just like a PC, with certain exceptions that we will be covering in a moment. For example, True Faith takes High approval, therefore a Toreador NPC with True Faith would take High approval. As out-of-clan Necromancy takes High Approval, therefore a Ventrue NPC with out-of-clan Necromancy takes High Approval."except experience points may be added to reflect the length of the chronicle."
The local chronicle begins from when the genre first started within the city with sanctioned play."The type is still subject to the Storyteller approval levels, but is one level lower than indicated on the venue chart."The oldest local chronicles are: For Cam-Anarch and Garou, Mar-1997. For Sabbat and Wraith, Nov-1997. For Changeling, Aug-1998. For Mortals, Sep-1999. Mage is tentatively set at May-2001.
Type refers to the chart in Chapter 1 of the various genres. For example, Gargoyles are listed as High approval in the Cam-Anarch venue as PC's. A NPC Gargoyle in Cam-anach is therefore Mid approval. Gargoyles are not listed as PC's in Sabbat; they are Top approval in that venue as a PC. A NPC Gargoyle in Sabbat is therefore High Approval."Venue-specific antagonist, such as Fomori for Garou or Autumn People for Changeling, are allowed with Low Approval, except for those eligible as Player Characters in other venues, which require Mid Approval."
An approved Venue Style Sheet (VSS) can specify a venue antagonist. A venue antagonist is one which will be a constant threat and adversary to the player characters. Specific antagonists who show up once, or are not reasonably numerous are not general anatagonists to the venue."Players may only play Non-Player Characters whose Power Class is available as a Player Character based upon either the Players Member Class, or the Member Class of the Storyteller sponsoring the Non-Player Character."If the venue antagonist is not listed as a type available as a PC in one of the supplements (for example: Inanimae is not listed as a type anywhere), then the venue antagonist type is Low approval. If it is listed as a type available (for example: Gargoyle is listed as a type in the Vampire supplement), then the venue antagonist is Mid Approval. Even though any type is possible as a PC with Top approval, those not specifically listed in a supplement remain Low approval for a venue antagonist.
Please keep in mind the cross-over rules and the reasons behind them when setting up these antagonists.
Example: In a changeling venue, Autumn People and Dauntain could be defined as a venue antagonists. Dauntain are listed as a possible PC type in the Mortals supplement and Autumn People are not listed anywhere. A venue antagonist Dauntain would be a Mid approval NPC. A venue antagonist Autumn Person would be a Low approval NPC.
Example: In a town in the wilderness, packs of typical Lupines who will attack the walking dead on sight would probably be considered an antagonist to the venue. A Silent Strider Emissary to the Prince's Court, probably would not be. A typical pack of Lupines, as they are available as a PC in another venue, will be Mid-approval NPC's if defined as a venue antagonist.
Example: Typical Sabbat packs might be setup as a venue antagonist is a combat heavy Cam-Anarch venue. On the other hand, a single Tzimisce antitribu Infernalist would not be a venue antagonist.
Example: The venue antagonists for a Mortal venue which focuses on vampire hunting, would be typical vampires. A Baali-Child of Gaia Abomination would not be considered a venue antagonist in that venue. Such is not going to appear in numbers in the venue and be a frequent antagonist.
Example: The venue anatgonists for a Giovanni focused game (i.e. as defined in their VSS) might be typical wraiths, or the local Hierarchy. Either will be Mid approval NPC's as they are available as PC's in the Wraith supplement.
"Power Class" refers to Generation for Vampires, Rank for Garou, etc. Using the sponsoring ST's Member Class (MC) is a change made in 5.1"Any of these restrictions may be superseded with High Approval"
To go beyond what is listed here will take a minimum of High approval.