Assaults are an alternative way to capture forts. In an assault, Archers, Heavy Infantry and Light Infantry attempt to overpower fort's garrison in a modified land combat.
Compared to sieging, an assault can capture a fort much faster but results in more casualties. A common use for an assault is to either retake a recently captured fort or finish up a siege when the fort has been breached. An assault can also be used to capture unharmed forts by micromanaging the assault.
Assaults have hidden mechanics which severely punish sending too few or too many units which often leads to massive casualties.
Key elements for an assault
- Fort level: Higher fort levels require more units for the assault. This also causes more casualties.
- Dice: Random dice rolls determine base damage for both sides.
- Army: Infantry in the army participate in the assault.
- General: Martial level increases strength of the assault which reduces casualties.
Each day, the garrison attacks all units in the assault and all units within the combat width attack the garrison. The assault ends when the garrison is defeated, the assault is defeated or the siege ends.
When to assault
Exact conditions for assaulting are difficult to calculate because of random dice rolls and multiple variables affecting each other.
Some recommendations can be given based on calculating results on different situations. This gives a good chance to capture the fort with reasonable casualties.
- Forts should be assaulted when they have less than 50% garrison remaining.
- With a breach, the fort should have less than 75% garrison remaining.
- All units should have a full strength and at least one unit should have a full morale.
- Recommended amount is 4 units per fort level.
- General with 5+ martial needs 3 units per fort level.
- General with 10+ martial needs 2 units per fort level.
- Consolidating can be used during the assault to reduce casualties.
There is still a small chance (< 10%) that the assault runs out of morale before the fort is captured. However the weakened garrison should surrender on the next siege tick. 50% more units can be added to prepare for the worst case but this will increase casualties.
33% of the units can be removed if the fort has less than 25% garrison remaining (or less than 50% with a breach).
Please report results of following these recommendations in the discussion page, especially on failures.
Micromanaging can be used to capture unharmed forts with only small losses. This is achieved by controlling the size of the assault. Normally you need to send more units to have some reserve against losses. With a separate reserve the manpower can stay closer to the optimal value which reduces losses significantly. Additionally the assault won't run out of morale because fresh units keep joining in.
Both infantry and mounted units are needed. Purpose of the mounted units is to keep the siege active without participating in the assault. Light Infantry is recommended as the infantry because of their low cost and weight. Chariots or Light Cavalry is recommended as the mounted unit for the same reason.
The table below shows how many units are needed in the worst scenario. With average dice rolls, the reserve can be halved. All values are per fort level.
|Martial skill||Infantry in the assault||Mounted units in the siege||Infantry in the reserve|
Main group with a reserve
The idea is to have a separate reserve which moves in and out of the assault refreshing the assault force. This can be used assault forts optimally with a minimal amount of losses. However pausing the game or very fast actions are required when refreshing the assault.
- Send all units to the fort.
- Split the army to a main group and a reserve (according to the table above).
- Send the reserve to any adjacent tile.
- Start the assault and unpause.
- After several days, pause and move the reserve back to the fort.
- Select both armies and reorganize units (B). Don't merge (G) or all units get locked in the assault.
- Replace weakened units in the main group with fresh units from the reserve.
- Select the reserve, consolidate (K) and send it to any adjacent tile.
- Repeat until the assault is over.
- Pausing the game is important. The reserve will automatically join the assault if a day passes while they are in the fort.
- The reserve should be moved back to the fort within 7 days. Their movement gets locked if they progress over halfway to the next tile.
- Keep an eye on the morale when reorganizing. Mix high and low morale units to ensure there is at least one high morale unit for every wave.
- For optimal execution, refresh the assault when the manpower drops below the optimal value.
- With the recommended amount of mounted units, the assault (and the siege) automatically pauses if the manpower drops too low.
The idea is to split the reserve to multiple armies which join the assault one by one. This works even without pausing the game but it's difficult to determine how often armies should be sent because of random dice rolls. Poor execution can lead to a failed assault with big losses.
- Split the army to a main group and a reserve (according to the table above).
- Split the reserve to a few armies.
- Send the main group to the fort.
- After a few days, send the first reserve.
- Repeat until all reserves are on the way.
- Start the assault instantly when the main group arrives at the fort.
- Merge (G) and consolidate ('K) reserves to the main group when they arrive.
- The assault takes less losses when the garrison gets weaker. More and more days should be waited before sending later reserves.
- With recommended amount of mounted units, the assault (and the siege) automatically pauses if the manpower drops too low.
- For easier execution, use more infantry in the main group and then send whole reserve as one group.
Dice & Damage
- An assault has a base damage of 0.08.
- A fort has a base damage of 0.18 and a 90% damage reduction.
- Each side rolls a dice from 1 to 6 every 5 days, increasing the base damage 0.02 per pip.
- A breach reduces the base damage by 0.1 which means the assault takes 33% - 50% less damage.
- A full strength assault deals damage equal 3% - 6% of maximum garrison.
- A full strength garrison deals damage equal 6.66% - 10% of maximum assault (3.33% - 6.67% with a breach).
- The garrison deals damage all units in the assault.
- Only Archers, Heavy Infantry and Light Infantry can participate in assaults.
- All unit types are equally effective at assaulting. But Light Infantry should be preferred because of their lower attrition weight.
- All modifiers such as discipline, offense, defense, morale damage taken, etc. don't have any effect at assaulting.
- An assault requires an active siege which needs at least 4000 manpower per fort level. Any units count for this limit.
- The assault stops instantly if the manpower drops below the limit.
- The army should have extra units to cover losses from the assault and also from attrition.
- Units can't retreat from the assault.
- All valid units participate in the assault, even if they are in a different army.
- The army should have units that can't participate in assaults (like Light Cavalry) to keep the siege active.
- It's recomennded to assault with only a single unit type because consolidating during the assault reduces casualties.
- Every fort level adds 1000 manpower to the maximum garrison size. Garrison size can be modified with Fort Maintenance setting.
- Every fort level increases combat width by 3000.
- Combat width sets the minimum amount of manpower required to assault effectively.
- Combat width also sets the maximum amount of manpower which can deal damage to the garrison.
- Martial skill of the general increases the assault ability by 10% per level (the tooltip states 5% per level which is incorrect).
- Assault ability can also be increased from an invention.
- Assault ability increases strength of the assault which means that less units are needed to assault effectively.
Optimal amount of manpower
Fort level and assault ability (mainly from general's martial skill) determines the optimal amount of manpower. Values are calculated below:
|Fort level 1||3000||2728||2500||2308||2143||2000||1875||1765||1667||1579||1500||1429||1364||1305||1250||1200||1154||1112||1072||1035||1000|
|Fort level 2||6000||5455||5000||4616||4286||4000||3750||3530||3334||3158||3000||2858||2728||2609||2500||2400||2308||2223||2143||2069||2000|
|Fort level 3||9000||8182||7500||6924||6429||6000||5625||5295||5000||4737||4500||4286||4092||3914||3750||3600||3462||3334||3215||3104||3000|
If the assault doesn't have enough manpower:
- Assault deals reduced damage (proportional to how much manpower is missing).
- Assault takes increased damage (proportional to how much manpower is missing).
- For example with 50% manpower the assault takes double damage. This will quickly destroy any remaining forces.
If the assault has too much manpower:
- Damage doesn't increase over the limit so damage from extra units is wasted.
- All units still take damage which results in bigger losses.
combat_width = 3 * fort_level
assault_ability = 0.1 * martial_skill + other_sources
effective_assault_strength = min(assault_strength * (1 + assault_ability), combat_width)
Fort deals damage to all units in the assault.
base_damage = 0.18 + 0.02 * roll - 0.1 (with breach)
morale_damage = base_damage
strength_damage = base_damage * fort_strength / (effective_assault_strength * 0.001)
base_damage = 0.08 + 0.02 * roll
strength damage = base_damage * 0.1 * effective_assault_strength