The big idea behind Westphalia is that while y'all are negotiating to end the war, y'all are still clobbering each other, because success on the battlefield makes it easier to get what you want in those talks. This meant the game needed to have a bifurcated structure, one that alternated Diplomacy Phases and Military Phases - carrots and sticks.
You would think that a designer with over three dozen wargames to his credit wouldn't have any problem with the stick part of that equation, but it's actually the thing that gave me the most trouble. And until the military stuff worked, none of the rest of it worked either; while the structure of the thing might be bifurcated, the two aspects of the game needed to fold into each other, otherwise what would be the point?
An early, mapless version of the game went something like this: the acting player declares an attack on an enemy. Each player commits troops, and then the defender's allies have the option to commit their troops in support. It was a very straightforward mathematical thing, with troop totals modified by cannons, and victory resulting in the acquisition of Leverage, a commodity that seemed awfully important in early versions of the game but was ultimately excised. It was very clunky, and because Leverage didn't really work, the military stuff didn't really work. Additionally, it was slow, as every time there was a combat, everything would stop so the defender could try and cajole their allies to intervene, and the attacker would try and cajole them not to.
Another version of the game had a combat system that used a hand of combat cards held by each player, and it being a negotiation game naturally these cards could be traded. That took even longer to resolve, and the tit-for-tat card play was kinda boring garbage to be honest. On top of that, the designer in me didn't really want a lot of hidden information in my negotiation game. And, more practically, to have enough cards in a deck for six (at that time, seven!) different players to each have a hand of cards while leaving enough cards in the draw pile that they wouldn't become a known quantity, well, that's an awful lot of cards, and would cost us an awful lot of money, which increases our risk, and making a game for seven and only seven is already a massive risk.
Around the time Mary convinced me to change my parameters from seven and only seven to six and only six, I decided to represent the military element through map-play. Armies are represented by pawns that "contained" off-map Units, and they march from Area to Area, exerting control over territory. A player possesses a piece of territory that contains a disc of their color. Armies within an Area can convert enemy territory - replacing the disc with one of their own - by "peeling off" a Unit to act as a garrison.
Now, obviously the previous owner isn't going to be thrilled about that, and has a chance to stop it by Intercepting the acting Army with their own. This is an offer to have a battle. The acting player can accept it, or they can refuse battle, retreating and leaving the territory in enemy hands. How the battle works is that the defender - in this case, the one being Intercepted - has a combat strength equal to double their Units, and the attacker - the one doing the Intercepting - has a combat strength equal to their natural number of Units, plus 2D6. If the attacker total is higher than the defender, the attacker wins. Both sides take losses equal to the lower of the two die results, the loser loses a Prestige, and the winner wins a Prestige, and as you might recall from a previous blog-thing, Prestige is a commodity that lowers the rate at which a player accrues Debt, something that is always in high demand.
A key bit to all of this is that Interception always results in the end of the acting player's turn once the battle has been resolved or refused. So, why wouldn't you always Intercept when given a chance, why let your opponent convert any territory at all? Recall that to switch out your disc with one of theirs, that opposing Army needs to expend a Unit - this lowers the number of Units in their Army, making them more vulnerable for when you do attack. That's assuming your opponent doesn't refuse battle of course - and they're going to be more likely to hightail it if you have a clear numerical advantage. That's also assuming you want them to accept battle; sometimes, you merely want to chase them off and end their turn without actually getting into a fight. Essentially, you're making a feint, and hoping they don't turn around and call your bluff.
And all this might still sound like a cold numbers game, because if the defender has six units (strength of twelve) and the attacker seven, the attacker has a 72% chance of winning, right? There's no reason a defender will ever accept that battle if they can avoid it, right? Well, there's one other catch: if the attacker rolls doubles, they've committed a military blunder. They lose automatically, and is the only side that suffer losses. On any 2D6 roll, there's about a 17% chance of rolling doubles, though my rigorous scientific research has found that this probability increases if everyone else at the table chants "don't roll doubles" over and over again while the attacker is rolling.
The last few paragraphs have been fairly mechanical, so let's talk about what's actually being represented by this. Firstly, the focus isn't really on the resolution of the battle, but on the art of coming to grips with the enemy in the first place. Actual major battles of the sorts represented by a die roll in Westphalia are fairly rare in this period, because every time you agree to a set-piece battle, you risk losing your entire army. A good commander is only going to take that risk if they feel they can win, or if a better commander has given them no other choice, having chosen ground that their enemy cannot or will not yield. Outwitting one's opponent - correctly reading their intentions and making the right decision based on that - is key.
This I feel gives the proper weight and emphasis to the cat-and-mouse element of seventeenth-century campaigning, and embodies the risks and rewards of battle in a way that moves things along very quickly. Players who never risk battles will find themselves without enough Prestige to manage their ballooning debts; players who are constantly rolling them bones will soon see their armies reduced to ineffectual scraps. They've got to goldilocks it, but finding that sweet spot is tricky, especially as the territory held and Prestige gained will give them leverage in the negotiations that follow.