A discursive look at Napoleonic & ECW wargaming, plus a load of old Hooptedoodle on this & that

Thursday, 17 November 2011

Solo Campaign Siege System - worked example

This follows on immediately from my last posting, and this is me attempting to try it out with a historical example. To be specific, the Allied siege of Ciudad Rodrigo in January 1812, and - to be even more specific - this starts off as history, but as soon as the dice start rolling, anything can happen, as we know.

One inconvenience about real history is that it is not easy to get a handle on some of the data - at least in your own pocket campaign you would know all this stuff for certain.

Ciudad Rodrigo has a Fortress Value (FV) of 6 in my table. This also limits the garrison to 6 combat units. From the appendices in Belmas, I know that the French force consisted of a very large but raw battalion of the 34e Léger, a battalion of the 133e Ligne (who were Tuscans, I am interested to note), a couple of companies of Artillerie à Pied (12th and 13th companies of the 6th regiment), about a dozen engineers and various staff monkeys and administrators and that's about it. A bit less than 2000 men, and the Garrison Value (GV) of the 4 units is - well, 4. Barrié, the garrison commander, had succeeded to the post when the appointed commandant (Renaud?) had been captured while inspecting the fortress's herd of beef cattle (the cattle were also captured). To get back to the plot, Barrié did not wish to have the position, and is generally regarded as unimpressive - we'll regard him as officially "Poor" in the motivation/leadership department, so no bonus is added to the GV.

Wellesley's force is not so easy to pin down. It is well recorded that the actual storm was carried out by the 3rd and Light Divisions, with support from Pack's Portuguese brigade, but this siege system is more interested in all the troops Wellesley had at the siege. This will then cover everyone who was available for digging and providing a threat, and who could potentially have been involved in a storm. By this wider definition, we should include the 1st, 3rd, 4th and Light Divisions plus Pack's Portuguese. If we lump together the various attached rifle companies into an extra battalion, this gives a total of 34 battalions plus 4 divisional artillery companies; 38 divided by 4 gives an Assault Value (AV) for the Allies of 10, near enough, which we should raise to 11 in view of Wellesley (supported by Fletcher and co) rating at least "Good" on our leadership scale. Wellesley appears to have had about 18000 men in these combat formations.

The designated Allied battering train consisted of 38 heavy guns which were deployed as 5 batteries - that's quite a lot of guns for 5 batteries, but we'll go with a Battering Value (BV) of 5.

To summarise, then, the defenders have FV = 6, GV = 4, the attackers have AV = 11, BV = 5.

Week 1

Bombardment: French have GV of 4, thus roll 4D6 (I'm actually rolling dice, rather pathetically, as I type...) - they come up 5 3 1 1 - the 5 deducts 1 from the attackers' AV, but there are no 6s, so no hits on the siege guns (BV),
Simultaneously, the Allied battering guns (BV = 5) roll 5D6 - 5 4 3 3 1 (not very good shooting, maybe they get better with practice?) - no 6s, so no damage to the fortress (FV), but the 5 scores against the garrison, so 1 comes off GV.

Now FV = 6, GV = 3 (total = 9) for the French, while AV = 10, BV = 5 for the Allies. The Allies do not bother asking the fortress to surrender, since their AV of 10 is extremely marginal for a storm against the defenders’ (FV + GV) = 9. No storm

Week 2

Bombardment: French now roll 3D6 - they come up 6 4 2 - the 6 hits the battering guns, and reduces the Allies' BV by 1
Meanwhile, the Allied batteries (BV still 5 - doesn't get adjusted until the end of this phase) roll 5D6 - 6 5 3 3 2 - the 6 removes 1 from the Fortress Value, the 5 removes a further 1 from the garrison (GV).

Now FV = 5, GV = 2 (total = 7) for the French, while AV = 10, BV = 4 for the Allies. AV of 10 still looking risky for a storm against (FV + GV) = 7 - bad luck with the dice could be disastrous. The Allies don't summon the garrison to surrender, and make no attempt to storm.

Week 3

Bombardment: French now reduced to 2D6 - they come up 6 5 - cheers from the battlements - they have the range now! Allies lose 1 off each of AV and BV
Allied batteries roll 4D6 - 6 4 4 1 - that's another 1 from FV - those walls are looking a bit second-hand.

Now FV = 4, GV = 2 (total = 6) for the French, while AV = 9, BV = 3 for the Allies. The Allies still don't fancy the chances of a storm, and don't ask for a surrender.

Week 4

Bombardment: French roll 2D6 - they come up 1 1 - useless. There may be trouble about this...
Allied batteries now down to 3D6 - 5 3 4 - the walls are standing up surprisingly well, but that's another 1 off the garrison (GV)

Now FV = 4, GV = 1 (total = 5) for the French, while AV = 9, BV = 3 for the Allies. Another week might improve the situation, but Wellesley decides to storm the fort now rather than lose further time (it's only a test...).

The Storm:

Defenders' Storm Strength DSS = FV + GV + 1D6 = 4 + 1 + 2 = 7
Attackers' ditto ASS = AV + 1D6 = 9 + 5 = 14, which is no contest – Attackers win.

Thus the storm is successful. The attacking force lose 1/2 x GV = 1/2 = 1 from their AV in the assault, giving a final figure for AV of 8. The surviving garrison are taken prisoner. Total loss for the Allies during the 4-week operation is 1/10 of the %age loss in AV = 1/10 x 3/11 = 2.73% which, for a force of 18000, is about 490 men. During the storm, the French lose 1/2 of (ASS - DSS) = 3.5, which is more than enough to eliminate their last surviving GV point. Thus the French have lost 100% of their GV, and actual casualties are 1/10 of this - 10% of the original 2000 men is 200, and the balance are prisoners.

OK - that worked. I'll try a couple more to see how it goes. It's not as much fun as a tabletop siege with a model fort, though. On the other hand, it didn't take me an entire weekend.


  1. I like this...a lot. I can use this kind of info for my own campaigns, great idea and thanks for sharing!!!!!

  2. Hi
    Mathematical sieges are a bit frustrating! However I can not see another way...

  3. The great thing about solo gaming is that you never really lose! You also get to avoid someone showing up late, not remembering the rules or arguing.

    I notice there were no sorties by the defenders in the middle of a night to destroy some of the batteries and knock off the egineers as commonly happened during seiges. Work that into your game and see how it messes up the careful planning and entrenching that goes into laying seige.

  4. Monsieur l'Empereur - well you're right, of course. At the end of my previous post (where I set out how it is supposed to work) I mention (at least I meant to mention) that sorties are abstracted as part of the week's hostilities.

    Each "Bombard" phase is supposed to represent a week's assorted nastiness, so - to keep the game as simple as possible (which is the point) - I have assumed that sorties and countermining and various other things apart from firing cannons are all just included into the unpleasant things that the garrison can do to the besiegers, so the dice throws include all that - plus anything else I haven't thought of!

    I've recently been re-reading Jones' book on sieges, and it is surprising how inventive these guys were.

    Regards - Tony

  5. Monsieur Foy,

    Perhaps I missed it in the explanation. This would make for a fun scenario having to do small little skirmishes and seeing what kinds of casualties arise. It would also be interesting to see a set up of the fortress and walls. Rafael has a good paper model of the Vauban style walls and bastions. So much to do, so little precious time.

  6. I received an interesting suggestion by email from Mr Crick. He makes the point that, for purposes of final calculation of casualties, there is no reason why the Garrison Value (GV) cannot go negative. If we allow this in the last step of the example in the post, then the French defenders face the storm with a GV of 1, and lose a further 3.5 in the storm, reaching a final GV figure of -2.5. Thus their GV loss is 6.5 from an initial figure of 4, which is 162.5%. The regulation 1/10 of this is 16.25%, which, for a start-up garrison strength of 2000, is 325. Thus the French have 325 casualties and the remaining 1675 are captured - I like the variability - as Mr Crick says, it is dumb to be able to predict that the French killed & wounded will be exactly 10%.

    Similarly, in an unsuccessful storm, it should be possible for AV to go negative, though that would indeed be a terrible disaster.

    Just a small tweak, but I like it - useful if it is necessary to distinguish prisoners from other losses.


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