Guns of War units battling old fashioned armies

How would you handle a battle between a modern army, with their arquebusiers, musketeers, and reiters, and a medieval tech army, with their longbowmen, horse archers and heavy infantry?

My main concern is the Battle rating of units. A unit of longbowmen from DaW has a BR of 3. A unit of flintlock musketeers from GoW ha a BR of 2. Clearly, the battle ratings are not directly compatible, or else we would still be using bows today!

A simple solution that came to my mind is to halve the BR of old-fashioned troops when facing gunpowder era units. But I'm not sure it would be an accurate solution. Any ideas? Did I miss a conversion table somewhere?

Historically, a well-trained longbowman was more accurate and much faster than a well-trained musketeer; but, bullets and gunpowder were cheaper than arrows, and firing a musket was as simple as pointing in the general direction and pulling the trigger. Everybody fire a volley, reload, fire again - very little skill, apart from loading, which meant soldiers were much faster to train. "Here's a gun, pull this bit while pointing that bit at the enemy, training done."

I think the BR makes sense - the difference should be the cost for the unit.

Thing is, there are some very weird situations when we compare the BRs of medieval and modern units. Let's compare medieval heavy cavalry (BR 6) with modern demi-lancers (BR 5). The demi-lancers have a lower BR, but if we look at their equipment they have everything heavy cavaliers have, plus a more modern armor and a wheellock pistol! Discrepancies like this one make me think the two sets of rules were not meant to work with each other.

I do want to find a way to make them work with each other, though, because my campaign is going to have civilizations with wildly different tech levels (think spanish conquistadores in America).

The heavy cavalier's horse is armored, the demi-lancer's is not.  That is the main advantage the heavy cavalry appears to have

Oh, good catch on the armored horse. I still think it's not enough to balance the wheellock pistol, but it's definetely something.

On a related note, an heavy trebuchet has a BR of 6. A monstrous 200-pdr mortar has a BR of...2. That can't possibly be intentional.

Hi Olrox! It's all intentional and the two systems are completely compatible. Mix and match as desired. The unit data is calculated in exactly the same manner. 

Early gunpowder weapons are widely accepted by military historians to have been inferior to longbows overall. The reason that gunpowder weapons became predominant is that they were easier to recruit for, easier to train, and less expensive to equip. (Also, the culture that created yeoman bowmen faded away.) This is reflected in the rules as follows:

  • Any peasant able-bodied enough to be conscripted in the first place can be trained to be an arquebusier. In contrast, only 25% of peasants can be trained to be longbowmen.
  • Training and equipping a flintlock musketeer takes 2 weeks; in contrast, training longbowmen takes 3 months.

A 200-lb mortar has a very low BR because it is almost useless on a battlefield. It has an incredibly slow rate of fire and cannot attack targets that are at short range. But the chief advantage of gunpowder artillery is that it has longer range and does considerably more damage to stone fortifications. A heavy trebuchet at 500 yards will deal 500shp per day. A 200-lb mortar at 1,400 yards will deal 775shp per day. 

(CAVEAT: One thing that's not reflected in the Battle Ratings, but is reflected in the tactical combat system, is that gunpowder weapons ignore some armor protection. This is abstractly represented with a BR bonus in the Battle Rating system, but in general the assumption is that in the campaign system, commanders are deploying combined arms forces of units in a way that minimizes their unit's weaknesses and maximizes their unit's strengths. So, for instance, they don't deploy their heavily armored troops to charge a line of gunners. If you find yourself in a campaign battle where one side is all gunpowder and the other side is all heavily armored troops you could give the gunpowder troops a bonus to hit with each BR roll. However, this issue is not really specific to gunpowder per se. The Battle Rating system can yield anomalous results anytime you get a force of all one type of troop fighting a force of all another type. For instance, all Horse Archers versus all Pike will fight very different using the BR system than using D@W: Battles. This is because strictly speaking units have intransitive scissors-paper-rock relationships that can't be modeled with a linear BR.)

 

60 Heavy Cavalry: Unit AC(6) * uhp(6)/8 * Morale Mult((9/7)^1/2) * Speed Mult(1) * Formation Mult(1) * Combat Mult(2.47/2*6)/6= 6*.75*1.13*1*1*7.41/6=6.3

60 Demi-lancer: Unit AC(4) * uhp(6)/8 * Morale Mult((9/7)^1/2) * Speed Mult(1) * Formation Mult(1) * Combat Mult((2.47/2*6)+.2*(3*.9))/6+.25= 4*.75*1.13*7.95/6+.25=4.78

4*.75*1.13*7.41/6= 4.2

1 wheellock pistol is worth .58 BR

1 shield plus chainmail barding is worth 1.1 BR

Rules as written, the armored horse is double the battle rating of the wheellock pistol.

EDIT: In light of Alex's post, I can guesstimate why this might be so. armoring your horse does nothing against firearms, but basically doubles your survivability against any non-firearm weaponry, this is probably why the relative BRs are so disproportionate.  One helps greatly against a broad range of opponents(horse armor), while the other helps greatly against a relatively narrow range of opponents(pistol)

Thanks for the excellent answers! There's plenty of reason to keep using some of the "outdated" units, then. Guess the Imperial Cataphracts have not yet seen their last day...

[quote="Olrox17"]

Thanks for the excellent answers! There's plenty of reason to keep using some of the "outdated" units, then. Guess the Imperial Cataphracts have not yet seen their last day...

[/quote]

The Imperial Cataphracts? Are you perhaps thinking of.... THE WINGED HUSSARS?

I love Winged Hussars so much.

[quote="Alex"]

I love Winged Hussars so much.

[/quote]

Masters of bringing a lance to a gun fight and winning.  Endearingly referred to as "murderhorses" in the Europa Universalis IV subreddit.

Does the BR of gun units account for their morale check effects? That might be another source of potential difference if they do not.

(As I recall, firing gun units at normal units forces a shock roll in the same way that being damaged by magic does. Away from books at the moment so I might be off, though.)

already included, as are their armor piercing effects

Oh good! My players don't know this yet, but once they really upset the Empire, shiny newfangled gunpowder troops are going to start marching up from the heartland, so there'll be a lot of gunpowder vs normal in my campaign.