Sieges in Detail
When you begin a siege, the computer does a number of calculations. The first thing that is done is troop strength points are totaled up. Strength points are calculated just as any combat with the exception that only half of the troops are used in a fief and foot soldiers are not figured into the total. If the manager or fief owner is present in the fief their soldiers are added to the total as per regular combat. A thing to remember is that each keep level counts as 1000 strength points for the defender and keep levels around up to the next highest integer.
Once troop strengths are calculated the siege ratings of the attacker and defender are compared. If a bailiff is in place he is used as the defender, else if the owner is in the fief he is used, else if the manager is in the fief he is used, else a defender rating of 4 is used. If the attacker rating is higher than the defender rating the attacker rating is divided by the
defender rating. The result is then used as a multiplier times the troop strength to determine a new troop strength. If the attacker rating is less than the defender rating is then divided by the attacker rating and the result is used as a multiplier to calculate a new defender troop strength.
The next step is to compare troop strengths. The highest is then divided by the lowest. The resulting value (usually between 1 and 2) is then found on the following matrix and keep levels are added (if the defender has the advantage) or subtracted (if the attacker has the advantage.).
Keep levels added or subtracted
Advantage
1.1 1
1.2 2
1.3 3
1.4 4
1.5 5
1.6 6
1.7 7
1.8 8
1.9 9
2 or more 10
The following is the matrix we use once the attacker knows how many keep levels he is facing.. We index on keep levels and days of siege. For example a siege against a keep level 5 at 30 days would have a 30% chance of success for a storm, half that (15%) for negotiation..
Prob of Success Days of Siege (Nego. Surrend. half percent shown)
Keep Storm Loss Avg
Level 1st 10 days 20 30 60 90 120 180+
Forgive the format, the stuff below is straight from the C code.
Below is the current table, introduced in March, 2000, and replaces an older one (shown below this table) that had higher success rate for longer sieges of big keeps.
Level 1st 10 days 20 30 60 90 120 180+
0 95% 1% 200% 200% 371% 570% 969% 1938%
1 30% 1% 33% 45% 117% 180% 360% 1080%
3 25% 2% 28% 38% 98% 150% 300% 900%
5 20% 2% 22% 30% 78% 120% 240% 720%
7 18% 3% 20% 27% 70% 108% 216% 648%
9 16% 3% 18% 24% 62% 96% 192% 576%
11 14% 3% 15% 21% 55% 84% 168% 504%
13 12% 4% 13% 18% 47% 72% 144% 432%
15 10% 4% 11% 15% 39% 60% 120% 360%
17 8% 5% 9% 12% 31% 48% 96% 288%
19 6% 5% 7% 9% 23% 36% 72% 216%
21 5% 5% 6% 8% 20% 30% 60% 180%
23 4% 6% 4% 6% 16% 24% 48% 144%
25 2% 6% 2% 3% 8% 12% 24% 72%
27 1% 7% 1% 2% 4% 6% 12% 36%
29 0.8% 7% 0.8% 1.2% 3% 5% 9% 28%
30 0.5% 7% 0.6% 0.8% 2% 3% 6% 19%
40 0.3% 8% 0.3% 0.5% 1.2% 1.9% 3.72% 11.16%
50 0.1% 8% 0.1% 0.1% 0.3% 0.5% 0.96% 2.88%
80 0.1% 9% 0.1% 0.1% 0.3% 0.5% 0.96% 2.88%
100 0.1% 9% 0.1% 0.1% 0.3% 0.5% 0.96% 2.88%
This is the old table, in use until early March, 2000.
Prob of Success Days of Siege (Nego. Surrend. half percent shown)
Keep Storm Loss Avg
Keeplev Days 10 20 30 60 90 120 180*
{{ 0, 95, 100, 100, 100, 100, 100, 100},
{ 1, 30, 33, 45, 100, 100, 100, 100},
{ 3, 25, 28, 38, 98, 100, 100, 100},
{ 5, 20, 22, 30, 78, 100, 100, 100},
{ 7, 18, 20, 27, 70, 100, 100, 100},
{ 9, 16, 18, 24, 62, 96, 100, 100},
{ 11, 14, 15, 21, 55, 84, 100, 100},
{ 13, 12, 13, 18, 47, 72, 100, 100},
{ 15, 10, 11, 15, 39, 60, 100, 100},
{ 17, 8, 9, 12, 31, 48, 96, 100},
{ 19, 6, 7, 9, 23, 36, 72, 100},
{ 21, 5, 6, 8, 20, 30, 60, 100}
{ 23, 4, 4, 6, 16, 24, 48, 100},
{ 25, 2, 2, 3, 8, 12, 24, 72},
{ 27, 1, 1, 2, 4, 6, 12, 36},
{ 29, 1, 1, 1, 3, 5, 10, 29},
{ 30, 1, 1, 1, 3, 4, 8, 25},
{ 40, 1, 1, 1, 2, 3, 7, 21},
{ 50, 1, 1, 1, 2, 3, 6, 18},
{ 80, 1, 1, 1, 2, 3, 6, 14},
{ 100, 1, 1, 1, 2, 3, 6, 14}},
Anything over 100% is an automatic win. Keep in mind the calculation that is done first to determine which side, on the basis of keep level and commander quality, is superior. This will add or subtract up to 10 keep levels before using the above table.
Let's say def force / att force = 1.6 then 6 additional keeplevels would be added to the original keeplevel.
If the attackers value is higher then just the reverse happens
att force / def force = 1.2 then 2 keep factors are subtract from the keeplevel
If you storm a keep, you damage the fortifications and cause losses to the garrison. These losses, and the damage, do not get repaired as long as you have the fief under siege. If you storm a keep and take it, you also automatically perform the equivalent of a pillage on the fief and gain a few ducats for your trouble. Like all pillages, this decreases the population of the fief a bit.