Friend and I are discussing how this would work. The character in question is a Human Aristocrat 2, Fighter 4 NPC
I believe he's a CR 4
Aristocrat 2 = 1/2
fighter 4 = 3
Am I right? or is it a CR 5?
I believe he's a CR 5.
A heroic NPC has a CR equal to his total class levels minus 1. And a heroic NPC is defined as an NPC having at least one level in a player class.
A basic NPC has a CR equal to his total class levels minus 2. So if he was an Aristocrat 2 / Warrior 4 he'd be a CR 4.
However, these simple calculations are rather wonky, at least at high levels. An Aristocrat 16 is no where near as powerful as a CR 14 monster. A better, albeit slower, method of finding the CR of an NPC is by comparing its stats with the Moster statistics by CR table.
I usually count NPC classes as half a level when I CR things for my games; so, in your example he would be a CR 5
Aristocrat 2=1
Fighter 4=4
Adding NPCs: Creatures whose Hit Dice are solely a factor of their class levels and not a feature of their race, such as all of the PC races detailed in Races, are factored into combats a little differently than normal monsters or monsters with class levels. A creature that possesses class levels, but does not have any racial Hit Dice, is factored in as a creature with a CR equal to its class levels –1. A creature that only possesses non-player class levels (such as a warrior or adept) is factored in as a creature with a CR equal to its class levels –2. If this reduction would reduce a creature's CR to below 1, its CR drops one step on the following progression for each step below 1 this reduction would make: 1/2, 1/3, 1/4, 1/6, 1/8.
Found the actual lines of text from the Gamemastery Guide which details this.
