Friday, September 24, 2010

DBA Solo Game - Baltic Greeks vs. Skythians

I finally picked up working the De Bellis Antiquitatis Solus rules again (found in the files section of the Solo DBA Development forum). I am not happy with the table that scores moves (i.e. determines which move is best for the non-player opponent to make), as it is too complex. So, I decided to simplify. Rather than five levels of aggression for the non-player general (NPG), I reduced it to three. Rather than have that factor affect both the types of move preferred and the score of each move, I decided to drop the latter modifier. These changes made calculations much faster.

It also struck me, during the test below, that some moves into combat can be considered both combat moves and defensive moves. This has led me to consider cataloging all of the basic moves and naming them, so I can refer to them in the scoring system. Not sure if that is insane or not, but it is my current thought.

The game I decided upon needed to be vastly different than the previous ones - which should not be hard because they were almost all Polybian Roman versus Ancient Spanish - so I chose to use my new Skythian army. Rather than have both sides be NPGs, I decided that I would run the Skythian side and its opponent would be the NPG. Looking through the list of opponents, and what I had available, I resisted the idea of playing yet another Bad Going Infantry army (like the Thracians, of which I have two lovely armies) as it would be too similar to the Ancient Spanish with an NPG. Something really different would be the Black Sea Greeks (II/5i) - a hoplite army against a Light Horse one.

This is an interesting match-up because the Light Horse are weak in combat factors (+2 versus foot and mounted), but they quick kill Spears (which are +4 versus foot and mounted). Because of that, the Light Horse will kill the Spears 17% of the time, get no result 11% of the time, recoil 47% of the time, and flee 25% of the time. If the Light Horse get an overlap (+2 versus +3) the chances change to 28%, 14%, 47%, and 11%, respectively, so getting overlaps will be critical.

In the Greeks favor is that they have enough Psiloi to form Spear "T" formations, or three Spears in a line with one Psiloi in the rear directly behind the center Spear. This allows the Psiloi to provide rear support to all three Spears facing forward, raising their combat factors to +5. If this happens - and it should be the primary NPG tactic - the factors become +2 to +5 (8% to destroy the Spears, 8% no result, 50% recoil, and 33% flee), unless the Light Horse get an overlap while also being overlapped, in which case it is +1 to +4 (8%, 8%, 42%, and 42%, respectively). As you can see, the odds favor the Greeks heavily, but note that the worst result the Spears inflict is to force the Light Horse to flee. In order to win, the Greeks are going to have to either use their other elements, Auxilia and Cavalry, to destroy the Light Horse or they will have to start flanking them, which will break up the hoplite line and create gaps for the Light Horse to exploit.

This should be an interesting game.

Black Sea Greeks versus Skythians
Pre-Battle Sequence


1. Determine Your Army Composition
My army will be the Skythians (I/43) with 1x2LH(Gen) and 11x2LH. The army type is Mounted and the force type is Light Horse. Its condition type is that it Fears Bad Going.

2. Determine the NPG Army Composition
The NPG army is Later Hoplite Greek, Others (II/5i) with the following required elements: 1x4Sp(Gen), 7x4Sp, and 1x2Ps. This makes the army type Foot and the force type Spears. There are still three elements to select. The choices are 1x3Cv or 4Sp and 2x4Sp or 4Ax or 2Ps.

The first optional element to deal with (section 2.2.2 Selection Criteria for Optional Elements) is the Psiloi. As the force already has one Psiloi, it must select at least one more. Once that second Psiloi element is selected, however, the NPG army gains an additional force type, Psiloi Support, as it now has two sets of three Spears plus one Psiloi.

The next optional element is Spears. As the enemy force type is Light Horse, only two elements need be selected, so this criteria is met.

The next optional element is Cavalry. As the NPG army does not have four Cavalry elements it will select the one element available.

The next optional element is Auxilia. As the NOG army does not have four Auxilia elements it will select the one element available.

The NPG army is this: 1x4Sp(Gen), 1x3Cv, 7x4Sp, 1x4Ax, and 2x2Ps.

3. Roll to Determine the Attacker
The Skythian aggression is 4, while the Greeks are 1. The rolls determine that the NPG is defending.

4. NPG Determines the Terrain
Although the Greeks do not Favor Bad Going, the Skythians Fear Bad Going, so placing Bad Going terrain is to the advantage of the NPG. As the Greeks have a Home Topography of Arable they are allowed (up to): BUA (1), Road (2), River (1), Steep Hills (2), Gentle Hills (2), Woods (2), and Waterway (1).

I am still fleshing out the terrain selection and placement rules, but I thought I would give you my thought process.

First, as a BUA is allowed, I determine if that will be in play. A BUA gives the defender more control over the board as it restricts the attacker from not being able to select two sides as the favored side when determining baselines. (Essentially, it changes the odds that the defender will get the baseline that they want.) As mounted have a hard time attacking BUA, and I have plenty of Spears to defend it with, using a BUA is favorable to the NPG.

The primary advantage of the Skythians is their mobility, especially around the flanks of their opponents. To hinder that mobility it is best to place Bad Going terrain close enough to the board edges so that elements must go through the terrain. Further, it is best to use line of sight-blocking terrain to hinder the enemy's command and control, should they try to sweep around the flanks. Given my LOS-blocking, Bad Going terrain choices, Woods are my favorite. So two Woods it is.

The basic plan is for the Greeks to dominate the center of the board, anchoring their flanks either between two Woods, or the BUA and a Woods, depending upon which board edge they get as their baseline. So, using those three terrain pieces, the goal is to set it up such that:

  • There is no gap 40mm or wider between the Woods or BUA and the board edge(s).
  • The distance between each terrain piece is roughly the frontage of the Greek army, no matter which baseline the Greeks end up getting.
As the NPG is Psiloi Support and the enemy Mounted, you should already have in your mind the basic deployment. The NPG will group the elements into two sets of 3x4Sp plus 1x2Ps, garrison the BUA with 1x4Sp, leaving 1x4Ax, 1x3Cv, and 1x4Sp to be placed separately. So, that makes the frontage of the NPG army a maximum of nine elements wide, or 360mm. This will help you gauge the distance between the terrain pieces.

These factors help me determine that the BUA and two Woods will form a triangle, with the terrain pushed towards the edges, cutting off flanking moves. As I am allowed a Road, and Light Horse armies gain little advantage from them, I choose to run one up the middle, should I need to reinforce the BUA. (In hindsight, I should have selected two, so I covered all possible baselines I could get.) Here is the terrain placement for the game. (I'll go over troop deployment and baseline selection later. I just forgot to take a picture before putting all of the troops on it and rotating it.)


5. Roll for Baselines
As I am the attacker, I get to choose the favored edge for my baseline. However, because of the BUA placement I am limited to only two of the four edges for my choice. My roll indicates I don't get my choice and I end up with the BUA on my right flank, as shown in the picture above. (All pictures are taken from the Skythian baseline.)

6. Deploy the Camps
As the NPG had a BUA, it had no camp, so that decision did not have to be made. The Skythians (I) placed my camp in the far left corner, as far away from the BUA and road as possible.

7. Deploy the Defending Army
7.a. Divide the NPG Army into Deployment Blocks
As indicated earlier, with the NPG army a Psiloi Supported force type and its opponent a Mounted army type, two of the deployment blocks will be two sets of 3x4Sp plus 1x2Ps. With the BUA on the board, the third deployment block will be the 1x4Sp garrison. That leaves 1x4Sp, 1x4Ax, and 1x3Cv, none of which are defined to work together in a deployment block, so they become three separate blocks.

7.b. Divide the NPG Deployment Area into Deployment Zones
The deployment zones are:

  • The open area on the Greek left flank (the right side of the picture above).
  • The woods on the Greek left flank.
  • The open area between the woods.
  • The BUA.
Note that a battle plan goes with every terrain setup, so the deployment zones, and how they are utilized, are mostly pre-defined.

7.c. Determine the Deployment for each NPG Deployment Block
As mentioned previously, one deployment block, 1x4Sp, will go into the BUA. As the battle plan for this terrain setup calls for placing the Spear T formations in the center, between the two woods (after the battle line advances, of course) that only leaves three one-element deployment blocks to commit.

At this point, I will admit that I have no rules for determining the position of these elements. So, I am stuck with either logic, dice, or both. I choose both.

The 1x4Sp element, along with the two Spear T formations can be placed in one of three configurations, shown below.


Essentially my decision was either to place the single element on the left or right of the two Spear T formations, or to put them between them. As that element is without Psiloi support, and is thus more vulnerable to a mounted attack I chose option B; to place the element in the middle of the battle line. As I did not want the General to be without Psiloi support, it was a normal Spear element in the center.

With the General being present in a Spear T formation, I had to decide which one, left or right. As the battle plan was to advance the right flank while executing a left wheel, I felt that having the General on the flank where the advancing was going on made more sense. In addition, this was the side where the enemy would be cramped and possibly pinned against the woods, so it was deemed safer. So, as shown in B in the figure above. the darker gray deployment block contained the General (with the Psiloi directly behind it).

With only two elements left - the 1x3Cv and the 1x4Ax - it got a little easier. Both of these elements are best suited for the flanks. I was unsure of whether the Greek left flank or right flank was more at risk. The right flank could be at risk if the Skythians got good early PIP rolls and moved quickly around that flank before the "door swung closed" (so to speak). Putting the Cavalry there would help prevent that from happening, but once the line was anchored, the Cavalry's movement would be as constrained as their enemy's.

Putting the Cavalry on the left flank gave it the potential to move left into the wide open terrain, possibly making a charge if the Skythians somehow mounted a serious attack against the BUA. I

The Auxilia could start in the woods on the left flank, guarding it while the hoplites wheeled left. This would have made that end of the line very hard to attack. Putting them on the right flank makes them vulnerable until their flank is anchored on the woods, but once they were there, they had complete freedom to move about in the woods, and they might possibly even make a strike at the Skythian camp.

I rated the left flank a better spot for the Cavalry and the right flank a better spot for the Auxilia and gave the odds at 1-4 the indicated deployment and 5-6 the opposite. The 1x3Cv ended up on the left flank and the Auxilia on the right.

8. Deploy My Army
The first picture shows the deployment of both armies.

9. The NPG Army can Swap up to Two Element Pairs
There seemed to be no reason to change any element positions.

10. Determine the Initial Strategic Stance of the NPG
The process for this step is fairly simple:

  1. Calculate the Army Rating for Your Army
  2. Calculate the Army Rating for the NPG Army
  3. Divide the NPG Army Rating by Your Army Rating
  4. Lookup the NPG Strategic Stance
10.a. Calculate the Army Rating for Your Army
Basically, the Army Rating is calculated by adding up the combat factors for all of the elements in the army. However, some elements are worth more (or less) depending upon certain factors. As the NPG army is Foot,  my army rating is calculated using the combat factors versus foot.

1x2LH(Gen) +3 x 1 = 3
11x2LH +2 x 11 = 22
Total = 25

However, I said that elements are worth more or less, depending upon certain factors, and they are:

  • +1 if the opposing army has any elements that are quick-killed by this element
  • -1 if the opposing army has elements that quick-kill this element
  • +1 if the element is capable of multiple moves in a bound
As my army is entirely Light Horse, any modifiers will apply equally to the entire army. Light Horse quick-kill Spears, so as long as the NPG army contains Spears elements, the Light Horse will be worth an additional point. As Light Horse are not quick-killed by any elements that the NPG army has (at least, as long as it stays out of Bad Going terrain), it does not lose any points. Finally, as Light Horse are allowed multiple moves per bound, all the time, each are worth an additional point. At +2 points per element, that is an additional 24 points, for a total Army Rating of 49.

10.b. Calculate the Army Rating for the NPG Army
Using the same method:

1x4Sp(Gen) (+4 +1 -1) x 1 = 4
7x4Sp (+4 -1) x 7 = 21
1x4Ax +2 x 1 = 2
1x3Cv +3 x 1 = 3
2x2Ps +2 x 2 = 4
Total = 34

The -1 for the Spears reflects that Spears are quick-killed by Light Horse. The two Psiloi will be worth +1 point each on turn one, as Psiloi can make multiple moves on turn one, but it immediately disappears at the start of the NPG second turn.

Note: as there is a road in play, any element on the road temporarily adds +1 to their value due to the multiple move capability. Again, these values can fluctuate due to casualties, terrain, and enemy casualties, but the Army Rating is only calculated at the start of the NPG bound, before PIPs are rolled.

10.c. Divide the NPG Army Rating by Your Army Rating
34 / 49 = 0.69

10.d. Lookup the NPG Strategic Stance
Anything at 0.75 and below is Cautious and anything at 1.25 or above is Bold. The NPG is Cautious.

Let the Game Begin

Now that we've gotten the preliminaries out of the way, it is time to start the game. If you want to understand how the Tactical Engine, used to determine which choices the NPG will make, use the document Using the Tactical Engine in DBAS as a guide. There are extensive examples in that document.

Rather than give a blow-by-blow, I will hit the highlights.

By the Skythian turn five, the right columns surged around the Greeks' left flank. One element was trying to push past the woods and get into the Greeks' rear (or draw off some elements - doesn't quite work against a solo opponent though!), while two elements on the left were waiting for the Greek right flank to commit so they too could sneak around the woods.

First blood is drawn by the Skythians, however, when the Greek Cavalry is destroyed on an unlucky roll. Skythian 1-0.


On the Greek turn eight the hoplite battle line has made contact and literally won every combat roll after losing that first element. Of course, winning the rolls only mean recoiling or fleeing Light Horse. The Greeks will need to break ranks to overlap the enemy is they want to destroy something.

Note the Skythians on the left flank have started to move around the woods, while the element one the right had is actually in the woods, but still stuck in it. (Not too many times when the Skythians have a spare two PIPs lying around...) The Light Horse facing the Auxilia in the woods have wisely broken off from combat before they get flanked, or contacted by the Auxilia in the woods.


On the Skythian turn nine they finally get enough PIPs to really get in and attack the hoplites. Below you can see a Light Horse element hit the right flank of the Greek line. Because one Spears element had peeled off to attack the Light Horse in earlier turns, the General's element was exposed to the flank attack. Although the odds are not great for the Light Horse (2-6), a 6-1 roll would have ended this game quickly.

As it stood, the hoplite's left developed a gap which the Skythians exploited. The Skythian General attacks a Psiloi-supported Spears element, both of which were flanked. Here is where the Skythians got the good roll. The score is now Skythians 3-0, and I figure that this game is probably done for the NPG.


One the Greeks' turn nine they roll good PIPs and quickly reconstruct their battle line (save for the General on the right flank). Better yet, the Auxilia leaps forward and attacks the exposed Light Horse that recoiled from the General. As they are in Bad Going, the Auxilia destroy the Light Horse, bringing the score to Skythians 3-1.


On the Greeks' turn 10 they rolled a six for PIPs and were able to shore up the battle line. The Auxilia moved onto the right flank, the spare Spears moved towards the left flank, and the two Spears isolated on the left flank retreated, so a recoiling Light Horse would not automatically destroy one of them.


On the Skythian turn 11 the Skythians are poised for a big kill, possibly ending the game. In their right flank they have flanked a Spear while keeping the other Spear occupied.


Unfortunately for the Skythians, they lose the combat badly (being doubled). Even worse, the fleeing Light Horse ends up behind there Skythian General such that if the General recoils next combat, he is destroyed.


A note to any Fanaticus readers who saw my question regarding this situation. When I asked the question I thought the Light Horse to the left of the General had fled, but after recounting the score, it was only a recoil. However, that was after my question...
On the Greek turn 11 what should they roll but one PIP! The Greek hoplites flank the Light Horse still in combat on their left, eliminating it. The score is now Skythians 3-2. Although it looks like the Greeks are back in the game, the Greek line is shattered on the left and the Skythians are swarming all over.


The Skythian turn 12 does not grant a lot of PIPs, but it allows enough for them to move the fleeing elements from behind the Skythian General, removing the threat from a recoil. One element attacks the left end of the battle line, turning it around. Unfortunately, the hoplites hold (the result is a tie) and the game goes on. The Skythians just cannot win any rolls since turn nine.


The Greek turn 12 finds them with a good PIP supply, so the Psiloi springs from the battle line, attacking the Light Horse in the rear, helping to eliminate it. The score is Skythian 3-3. The Greeks could actually win this one!


Let's Pause for a Brief Moment to Review

At this point the Skythians have lost three Light Horse elements. As their elements were worth four points apiece, their Army Rating is now down 12 points from the original, for a total of 37 points. The Greeks are down one Cavalry, one Psiloi, and one Spear element or 8 points, putting their Army Rating at 26. Unfortunately at 0.70 that makes the NPG Strategic Stance still Cautious, so nothing changes. I just wanted to point out that these value change over time and it is possible for an NPG General to gain a little courage if things go their way early.

Now Back to Our Battle

The Skythian turn 13 proved to be the end. The Light Horse lined up with the General and swept in to attack the end of the hoplite line, where the Spears were presenting their rear, having finished off the Light Horse element last bound. In this case they must not have turned fast enough.


Skythians win 4-3!

Summary

Boy, this was one of those battles that you thought sure was going to go a certain way, but just would not seem to die. For the Greeks this is a really tough battle. They just don't have enough fast troops to be able to flank the enemy, especially when they are Light Horse. Add the quick kills in there and it is no wonder that the Greek NPG was cautious all along!

Lessons for Solo Gaming

First and foremost, this was a playtest of the solo rules De Bellis Antiquitatis Solus, trying to refine the Tactical Engine and add more to the deployment section of the rules. Although I did not do much of the latter - I still rely on generating a battle plan to match the terrain laid down, none of which have been adequately cataloged - I came to realize that a number of moves that I classified as Combat Moves can also be considered Defensive Moves, thus increasing the choices that a Cautious general can make.

What's next? Another revision of the Tactical Engine document, plus perhaps an update to DBAS itself.