(copy pasted from manual)
The attacker makes an attack roll. The defender makes a defense roll. These are compared. If the attack roll (with modifiers) is greater than the defense roll, it hits. If not, it misses. The attack and defense rolls are modified by a random number (which is added) and a fatigue penalty (which is subtracted).
Attack roll: attacker's Attack attribute + DRN - Fatigue penalty
Defense roll: defender's Defense value + DRN - Fatigue penalty
Once a hit is scored, a similar calculation is done to determine how much damage is done. This involves the attacker's damage roll minus the defender's protection roll.
Damage roll: attacker's Strength attribute + weapon Damage attribute + DRN
Protection roll: defender's Protection attribute + DRN (+ shield Protection if it is a "shield hit")
If the defender has a shield, the hit is a shield hit unless the attack beats the combined value of the target's defense and the shield's Parry value plus the random roll. If a hit is scored as a shield hit, the shield's Protection is added to the defender's protection roll.
Example: A Heavy Infantry unit has a broad sword, chain mail hauberk, half helmet and shield. It has a base defense of 10, gets a defense bonus of +1 from the sword, a defense penalty of -2 from the armor, and a defense penalty from the shield of -1. The shield's Parry value is 4. The actual defense is 10 +1 -2 -1 = 8. With the shield's Parry value, the unit's total defense is 12. The Heavy Infantry is attacked by a Vanjarl of Vanheim, which has attack 14. Neither unit has any fatigue yet. The Vanjarl rolls a 6, for a total attack value of 20. If the Heavy Infantry rolls a 7 or less, it is a clean hit and the shield offers no protection. If the Heavy Infantry rolls an 8 through 11, the Vanjarl scores a shield hit and the Heavy Infantry can use its shield's protection value in the damage calculation. If the Heavy Infantry rolls a 12 or higher, the Vanjarl misses entirely.
The Protection value used is the target's listed Protection value, unless it is a head hit. In case of a headshot, the target's helmet Protection value is used instead of the main Protection value. However, if it is a shield hit, the shield Protection is still added. The blow is assumed to have glanced off the shield and hit the target in the head. If the damage roll is greater than the protection roll, the difference is subtracted from the target's hit points. If the protection roll is equal to or greater than the damage roll, there is no effect.
Shield hits can damage or destroy the shield. A shield has a Resistance, which is the same as its shield protection value, +5 if the shield is a magic one. The attack has a Break value, which is equal to the damage of the attack before any Protection.
If the Break value is >= 3x the Shield Resistance, the shield is damaged.
If the Break value is >= 5x the Shield Resistance, the shield is broken.
An already-damaged shield which is damaged again has a 25% chance of being broken. A damaged shield has -20% Protection, a broken shield has -50% Protection. A magic shield (a real, equipable one) that is damaged will repair itself after the battle. If a magic shield is broken, it will be permanently destroyed and the commander will revert to his or her standard shield if he or she had one. Damaged or broken mundane shields will be repaired when they are in a province with enough spare production resources.
Dominions 5 uses anatomical locations to determine where an adversary was struck. An attack has a 50% chance of striking the adversary in the torso, 20% chance to strike the arms, 20% chance to strike the legs, and 10% chance to strike the head. Certain hits can cause afflictions, such as losing a limb. If someone loses a limb, it will be the one which was hit. This can be an arm, leg, or head. Losing your head is usually instant death, but this is not always true, for example in the case of undead and certain kinds of regenerating monsters, or those with multiple heads. Other types of afflictions include losing an eye, which can only happen on a head hit.
In order to score a hit on a certain part of the body, however, the attacker must be able to reach it. To score a head hit, attacker size + weapon length must be equal to target size. This requirement is one less to hit the torso and two less to hit the arms. Thus a human (size 2) wielding a mace (length 1) could hit a size-6 creature only in the legs!
Some monsters have their heads located lower than their size would indicate and therefore anyone attacking them will get a bonus to their reach. Lizards and dragons are very low and are two steps easier to hit when striking anything higher than the legs. Most four-footed beings like elephants and wolves are slightly lower than a humanoid would be and are one step easier to reach. Their lower stature does not mean they are more likely to be hit in the head (or any other hard-to-reach location). It is still only a 10% chance, but attackers with shorter weapons might be able to reach and hit them in the head in situations where their size might otherwise prevent it.
Also, some monsters lack certain hit locations. For example, a dragon has no arms and a gelatinous cube has no arms, legs, or head.
A significantly larger unit that attacks a smaller one will have an increased chance of hitting its target in the head and a lower chance of hitting it in the leg (20% head, 10% leg). To be considered “significantly larger” it must either be 2 sizes larger, or 1 size larger and be mounted.
Melee weapons in Dominions 5 come in three different types: slashing, piercing, and blunt. Each type has different effects when calculating damage. These are all calculated after the Damage vs. Protection calculation above, except for Piercing weapons which reduce Protection prior to the calculation.
Blunt weapons do 50% more damage when scoring head hits after the Protection value is deducted. They score 25% more damage toward shield destruction.
Slashing weapons do 25% more damage after Protection is deducted. They do 50% more damage toward shield destruction. If a slashing weapon scores a leg, arm, or head hit that costs a target greater than or equal to 50% of its hit points, that body part will be chopped off. If a head is chopped off, this will kill the target if it had a head that was required for it to stay alive. (For example, a hydra does not fit that description.)
Piercing weapons reduce Protection by 20% prior to any calculation. This is the same mechanic as the Armor-Piercing ability, except that Armor-Piercing reduces Protection by 50%. This is multiplicative, so an piercing Armor-Piercing attack, will reduce Protection by 60% prior to calculations.
Two-handed weapons add 125% of Strength to damage.
Underwater effects: slashing and blunt weapons have an attack penalty equal to weapon length underwater, while piercing weapons do not. If a weapon does both piercing damage as well as another type, the underwater penalty is halved. Flails have an additional penalty of -1.
A weapon may be able to inflict more than one type of damage. If so, it has an equal chance of doing each type of damage, but will only do one of them during that attack. For example, the short sword does both slashing and piercing damage. It has a 50% chance of doing one of these. If it does not do piercing, it will do slashing, but never both.
In addition, weapons may have additional special effects, such as fire, cold, or magic. Damage is displayed in colored numbers above the unit that suffered the damage. Pale red is normal damage, dark red is bleeding, green is poison, etc. This can be very helpful in determining the effectiveness of your units and tactics.
(replaces Multiple Attack Penalty in previous Dominions) Every time a unit is attacked, it gets a point of harassment penalty. Each point of harassment penalty reduces the unit’s defense by 1. It is then reduced continuously by a percentage, so it goes down quickly if it is high and the unit is no longer being attacked. Mounted units are only half as affected, requiring two attacks to suffer one point of harassment penalty. A mounted unit completly surrounded by 1-attack-per-turn units bottoms out at -10 defence harassment penalty. A weapon with multiple attacks inflicts 1 point of harassment penalty for each one of its multiple attacks.
Fatigue is affected by a unit’s encumbrance value. The more encumbered it is, the more fatigued it will become during combat. Each time it attacks, it gains Fatigue equal to its current Encumbrance value.
For each 10 points of fatigue (rounded down) a unit has its defense reduced by 1. For each 20 points of fatigue (rounded down) a unit has its attack reduced by 1. Fatigue above 50 also makes critical hits more likely, and being fatigued unconscious even more so.
Repel is how Dominions represents the effectiveness of long weapons, such as halberds, pikes, and the like. If a unit attacks an enemy who has a longer weapon than the attacker, the defender may actually repel the attack and prevent it from happening. This occurs as follows:
This simulates the defender successfully placing his longer weapon between himself and the attacker. All of this occurs before the attacker’s strike is resolved. Note that units with low morale are more likely to be repelled, and thus using long weapons against low-morale troops is very effective. Also, units with claws and bites (weapon length zero) are easier to repel.
The repelling unit gets a lingering -2 to its Repel roll which is gradually removed over a short period of time. So it’s harder to repel attacks when they come in quick succession, and easier if they are spaced out in time.
The result of the repel attack roll is carried over to the morale check. This means that units with low defense will often get repelled even if their morale is high. In theory it's even possible for thugs with extremely high attack values to repel mindless units (who has morale 50 and are normally immune to repel) but that is unlikely to happen in a normal game.
Bear in mind that the defender gets one repel roll per weapon regardless of the number of attacks of that weapon. So ais just as good at repelling as a
Some units have multiple attacks. This may be due to multiple weapons, or just multiple methods of attack like biting, clawing, or many tentacles.
Attackers with multiple weapons have their attack skill reduced by the sum of their weapon lengths. Thus, it is much easier to fight with two daggers than with two swords. The Ambidextrous ability reduces this penalty by the amount of the Ambidextrous skill. Some weapons are considered intrinsic to a unit and do not cause multiple weapon penalties for the attacker. These are called bonus weapons. For example, the charioteers of Arcoscephale have both a spear and a shortsword, but because the spear is a bonus weapon (different from a normal spear) because it is wielded by the second man on the chariot while the driver fights with a short sword.
Some weapons, usually lance, deals bonus damage for first strike.
Charge bonus: Size + (Combat Speed / 4)
Charge bonus for flying units: Size x2
Flying units do not use CS based calculation even if that was better. The bonus was capped by STR / 2. However, if the weapon was heavy weapon, the cap increased to STR.
Missile combat is different from melee combat in that it doesn’t use defense values. Instead, the game determines which square a missile hits, depending on a unit’s Precision, and the range of the attack. If there are units in the square, they may be hit, whether they are friendly or enemy. Missiles can’t distinguish friend from foe.
If the range from attacker to target is greater than Precision/2 – 2 (half the Precision, minus 2) then the missile will deviate from the target. The amount of deviation is equal to the range x 1.25 / Precision. The game will randomly determine whether the missiles deviate long or short, left or right, or some combination. The actual distribution is a bell curve – most projectiles will fall within the middle of the deviation range, but some will land at the extremes.
Once the game decides where a missile lands (even if it is far away, that square is affected), any unit in that square may be targeted. The size of the unit influences who will be hit. If a square with a giant of size 4 and a human of size 2 is hit, the giant will be targeted two times out of three. Once the target is decided, there is a hit calculation that uses the following values:
Attacker: DRN + (Size points in the square) +2 if magic weapon
Defender: 2 + DRN + (shield parry value x2) – (Fatigue / 20)
If the attacker’s roll is greater than the defender’s then a hit is achieved. Damage is calculated identically to melee combat (see above). Most missile weapons add one-third of the unit’s Strength to the weapon damage value (plus a random number). Crossbows and some other weapons are armorpiercing, meaning that only half of the defender’s Protection value is used. Some spells can even be “armor-negating,” which means that armor affords no protection. Lightning spells are armor-negating. Fire spells are armor-piercing.
Precision values greater than 10 count double for the amount above 10. Thus, a Precision value of 12 is actually calculated as Precision 14.
Thus, the more units in a square, or the bigger the units in a square, and the more tired they are, the more likely someone is going to be hit by a missile weapon landing in that square.
While it may seem that missile units can’t shoot very far without having their shots deviate hopelessly, in practice massed units can deal severe damage to an enemy simply due to the number of projectiles in the air. Everything that goes up has to come down somewhere!
Some types of damage can cause the target to sustain additional damage. Others inflict their damage gradually, or increase fatigue instead of reducing hit points. These include fire, cold, poison, fatigue, paralysis, and drain.
Some units are not as susceptible to certain kinds of damage. In Dominions, this is represented by the concept of resistances. If a unit is resistant to fire damage, for example it is said to have fire resistance. This works identically to protection. It is like armor against fire. The standard resistance is 15, which will reduce damage as though it had extra protection of this number. Resistance to a damage type is unaffected by armour piercing or negating properties, unlike regular protection.
Elemental resistances provide double protection against fatigue damage from those attacks of the corresponding type. For example, Fire Resistance 5 grants 10 protection against the fatigue damage from heat auras.
Fire is generally armor-piercing, which means that a unit only gains half of its normal benefit from Protection. In addition, a unit may catch fire, which will subject it to additional burning damage until the fire goes out.
A unit that is burning takes 1d(size) damage each turn until the fire goes out (a die with a number of sides equal to the size of the unit, so for a Size 6 unit it would be 1d6). The chance of the fire going out is 25% + (fire resistance x2) + (cold scale x5) +100% if it is raining. All fire have a minimum 1% chance of being extinguished. If the province has heat scales instead, this is treated as negative cold.
A unit suffering cold damage may freeze. It will then take additional fatigue damage until it thaws. A unit that is freezing takes 2d6 additional fatigue points of fatigue damage each turn until it thaws. The chance of thawing is
25% + (cold resistance x5) + (heat scale x6) + (cold resistance)
Cold vulnerability counts as negative cold resistance. Units with 5 or more cold resistance, units with heat auras, and ethereal units will never freeze. Cold scales work like heat scales for burning: if it’s cold in the province, the chance of thawing is reduced by the scales.
A unit suffering from profuse bleeding suffers 10 fatigue and takes HP/20 damage each round. The chance of bleeding stopping is 10% + (regeneration value) and is divided by 2 if unit is underwater.
Poison works differently from fire or cold. If a unit takes poison damage, that damage will be suffered over multiple rounds, which is the amount of time it takes the poison to have its effect. This damage is spread out as evenly as possible. First, a total amount of damage taken is calculated, just like with any attack. Then, a unit will take 10% of the total damage (rounded up) every combat round until all of the damage is taken completely.
For example, if a unit takes 15 points of poison damage, it will take 2,2,2,1,1,1,1,1,1,1,1,1 points of damage consecutively in the following twelve combat rounds. In the first three rounds it will take 2 points per round, and in the last nine rounds it will take 1 point per round. On the first turn the unit takes 10% of 15, or 2 points, leaving 13 remaining. On the second turn it takes another 2, and then another 2 on the third turn. That leaves 9 points, 10% of which is 1 point each turn, for the remaining 9 turns.
Poison resistance has no effect on the duration of damage. Once the poison has taken hold, there is no additional benefit coming from poison resistance. Poison resistance which only comes into the initial calculation of the total amount of poison damage taken every time a unit takes poison damage.
Since poison damage is somewhat similar to bleeding and doesn't count as external damage taken, it does not wake sleeping units or break mistform/fog warrior effect.
Shock damage is always armor negating and can Stun a target.
Chance for Stun = 5% + (percentage of hit points lost from this hit) / 2
Stun prevents the affected unit from taking any action for one round.
Life Drain damage is not extra damage, but instead is a way for the attacker to restore his or her hit points and fatigue by damaging an enemy. Once damage has been calculated (if the target is a living unit), the attacker with life drain:
Increases his hit points with damage / 2
Reduces his fatigue by damage x 2
Weapons with partial life drain are less potent, and only the first 5 points of damage dealt are treated as drain. The remainder are considered normal damage only. Life Drain cannot increase a unit’s hit points above 150% of its maximum hit points +10. Lifeless units only take 25% damage (after Protection).
Acid damage can inflict Rust. It has the same chance as fire. Only units with iron weapons or iron armor can be affected by Rust.
Rusty armor can be damaged if it takes a hit in combat.
Chance for Rusty armor to be damaged = damage inflicted (before armor protection, but after shield protection) * 2%
Rusty weapons have a 25% chance of being damaged when they inflict a hit on something. Damaged weapons have their damage reduced by 2, except for blunt weapons which have their damage reduced by 1.
Paralysis is a type of damage that, as you might have guessed, paralyzes the target. The number of combat rounds the paralysis lasts (the duration) is determined by the number of paralysis points done and the target's size.
Duration = (Damage – victim's Size) / 2
If that is all the paralysis damage taken, then the target is only paralyzed for that many rounds. However, if the target takes additional paralysis damage, a new duration is calculated, and the target takes half as many points of damage as the lesser of the new or old durations. In other words, if the target is already paralyzed:
Damage = (minimum of old and new duration) / 2
This damage can never exceed 5 points. The new duration will be the greater of old and new duration (not cumulative), so if the new attack has a longer duration, the target will be paralyzed for longer.
Fatigue damage adds to a unit’s fatigue rather than subtracting from its hit points. Units fall unconscious when they reach 100 fatigue and start to take hit point damage once they have reached 200 fatigue, which is the maximum fatigue reachable. For each time fatigue damage is taken, each 50 fatigue points beyond 200 fatigue inflicts 1 point of hit point damage, rounded up. This means that even 1 point of excessive fatigue inflicted will cause 1 hp damage, and 51 points of excessive fatigue will cause 2 hp damage.