I try to calculate the BR of one of my NPCs for a platoon scale battle.
The formula in the Campaign Book is:

(Number of Creatures) x (Creature’s AC+1) x (Creature’s HD) x (Creature’s HD + 1) x (1 + Creature’s # of Special Abilities)/(8 x # of Infantry per Regular Unit)

I wonder about the last part. Do I always have to divide by 8120 or does the platoon scale reduce it to 830? What if the NPC is mounted, is it then 8*15?

The platoon scale reduces it to 30, I believe. Not 100% sure but I’m pretty sure.

If the NPC is mounted, it gets more complicated, because then they are not a standard unit; the NPC and the mount both have stats and both contribute to the battle. Rules for calculating the BR of a mixed unit are in Chapter 8 of Battles and are much more complicated.

You could probably find a tool to calculate it (I’m fairly sure there’s a spreadsheet somewhere for it) or ballpark it by averaging the stats of the NPC and mount, then calculating the unit as two creatures of the average.

I think you’re correct, yes. I think this is especially correct for heroes, since their relative effectiveness goes up against smaller units. (contrasted with just a platoon scale battle of regular units, where the change in scale is consistent across all units and therefore divides out to be the same number)

Using the rules in Battles what I think you’d end up doing is calculating the BR of a unit of identical heroes, then you’d have to divide out to get the single BR at either company (60 horse) or platoon (15 horse) scale.

I don’t think it’d be a mixed unit, I still think that’s a cavalry unit - even if it’s a guy on a dire wolf or something (there’s different values for mounts that will fight by themselves I think).

A mixed unit would be more like a shaman and his totem animal, perhaps.

Whether or not all that’s worth it depends on how complicated the hero is, I think.

You divide by whatever scale you are using for the battle. The important thing is that all the Battle Ratings be at the same scale, and that whatever scale you use to calculate the BRs of the units is also the scale you use to calculate the BR for Heroic Forays.

I often find that platoon-scale works best for battles including PCs, as it allows for a finer granularity of casualties, a greater impact for PCs, and heroic foray bidding that is more meaningful.

For a platoon-scale infantry unit you’d thus divide by 30.

I used the wrong phrase because tired. You’re right, it’s not a mixed unit as defined by Battles.

What I meant is that it’s not a standard infantry unit anymore, and so you have to account for the mount, which is more complicated than using the quick formula in Campaigns.

But that also means that a platoon-scale mounted hero needs to divide by 15 right?

I tried to calculate the hero twice, once with the platoon-scale campaign rules and once with the more detailed and complicated battle rules.
The result was 6.3 in both cases as long as he was using a lance!
Guess its good that the values match but I wonder why one only the campaign rules include the scale.

You don’t need to divide by 15 for mounted units because the division is specifically by number of infantry in a unit, not by number of guys in the actual unit being calculated.