EHamilton, thanks for your comments. I’ve made some annotations below.
The BR table seems to suggest that the formula has a linear dependence on HD. That is, the rating of a human/orc heavy infantry is 2, a gnoll (2 HD) is 4, and a bugbear (3 HD) is 6. But the formula below says that the HD dependence should be quadratic, scaling as HD*(HD+1).
I thought maybe the discrepancy might be due to human/orc infantry having access to better armor (plate, versus chain-equivalent for the monsters?), but that still doesn’t explain the gnoll vs bugbear vs ogre linearity.
APM: The various troop BRs were derived by assigning an equivalent of fractions of various special abilities. Generally, the weaker the creature, the more importance I placed on their equipment. Some creatures actually have “negative” special abilities if they are irregulars (in DAW: Battles this is made much more explicit).
For example, conscript/militia and goblin light infantry and slingers count as having -0.25 special abilities: (120 / 240) x (0.75) x (1.75) x (1+ -.25) = 0.5
Human light infantry count as having 0.5 special abilities:
(120 / 240) x (0.75) x (1.75) x (1 + 0.5) = 1
Orc light infantry count as having no special abilities
(120 / 240) x (1) x (2) x (1) = 1
Orc heavy infantry count as having 1 special ability
(120 / 240) x (1) x (2) x (2) = 2
Gnoll heavy infantry count as having 0.33 special ability
(120 / 240) x (2) x (3) x (1 + 0.33) = 4
Bugbear heavy infantry count as having no special abilities
(120 / 240) x (3) x (4) x (1) = 6
It looks like the value for Ogres is wrong, though. In an earlier draft, there were only 25 ogres per unit, but now there are 60.
Possible unintended consequence of the morale system (maybe I’m misunderstanding this): The “rally” bonus applies only when the army gets to make a morale bonus (losing entire unit, or cumulative 1/3 of total unit number), but will let units with very high morale (plus a charismatic leader) get a +50% BR boost. A unit with adjusted morale 10 (including CHA bonus) would rally constantly! This creates a perverse incentive to include a bunch of really weak units that will die fast without having much effect on total BR – so that the main army has more chances to gain rally bonuses. I’d probably revise the trigger conditions for morale rolls to be based on something other than the raw number of units lost, maybe based on BR losses just like the modifiers are.
APM: While that is a theoretical possibility, I’ve run dozens of battles in a series of ACKS campaigns and never seen that occur. Most units have a ML of 0; some go as high as +2. Most leaders have a Morale Modifier of +2 to +4. Armies making morale checks are usually at a -2 penalty (for having lost more BR of units than the opposing army). The net result is that most morale rolls are made at a +2 bonus. About 16% of units will Rally, about 8% will Flee, about 25% will Waver, and the rest will Stand Firm. The ones that Waver or Flee end up much worse off on the following turn.
I like the heroic foray concept, although I’m worried about the scale mismatch between small heroic parties and such huge armies, especially when it comes to engaging ranged troops with heroes on an open field. If you launch a modest BR 1 foray and find yourself facing 240 goblin slingers, winning initiative would probably be a high priority! Quite aside from survivability concerns, it seems like these kinds of fights would take a substantial time (and collection of dice!) to play out.
APM: The assumption is that the PCs are 8th level and above. PCs of lower level than that are allowed to do heroic forays, but they are not really well-suited for wading into battle against masses of enemies. High-level PCs will slaughter low-level enemies, though. For example, a wizard with fly, protection from normal missiles, and a wand of fireballs will wipe out 240 slingers very, very quickly.
It’s up to the Judge to decide what the PCs face in their foray. Generally I assume the PCs are seeking out the toughest troops. If there is a unit of 120 Bugbear (BR 6) in the battle, let the PCs foray against the Bugbears. Then they’d fight 20 bugbears (BR6/6 = 1; 120/6 = 20).
Also keep in mind that for smaller battles (skirmishes) you can reduce the number of troops that one point of BR represents. For example, let’s say the battle is between 480 troops on a side. At 120 troops/unit, that’s only 4 units per side. That’s not very interesting. So, instead, let every 20 troops counts as a unit. Each side has 20 units, which will make for a longer, more interesting battle. It also allows heroic forays to be against units of 20 troops rather than units of 120 troops.
Since character level and battle size tend to increase in direct proportion, usually the optimum unit size tends to be in proportion to the level of the PCs.
One possible solution I might try: specify that each unit has a smaller number of captains (say, 1st-3rd level types), and disproportionately include them in the stake, replacing the full horde. That reflects the way I visualize a foray. It isn’t that the heroes exclusively attack a group of 120 goblin slingers to wipe out to the man, it’s that they target the leaders of that group and try to execute a precision strike to incite a panic. So a fight against a 120-goblin slinger unit would instead become a fight against a 3rd level goblin captain, a half-dozen 2nd level guards, and a dozen veteran 1st level slingers from that unit. If the heroes kill that command portion of the force, they’ve effectively destroyed the cohesion of the larger group and routed it.
APM: The math behind heroic forays won’t really work if you handle it this way. If you want the PCs to fight against major enemy NPCs, you’d be better off using the Heroes versus Heroes foray rules, with 0 BR staked.
Oh, and I’m wondering about the rationale for only allowing infantry pursuit after all opposing cavalry units are destroyed, and providing a throw bonus for destroying cavalry. I don’t see any problem mechanically, I’m just curious about the simulationist motivation and its historical precedents. This seems to be replacing the usual approach of basing pursuit modifiers off the terrain and relative travel speeds of the armies.
APM: The pursuit of enemy forces following a battle has always been primarily the responsibility of cavalry. Likewise, cavalry is the best troop type to screen a retreat.