How Combat Works in Meridian

General Combat Equations

Combat is now more standardized in Meridian. Most of the combat functionality was moved to the Battler superclass instead of being separated in the Monster and Player subclasses.

Combat revolves around the Offense and Defense values of every battler. For players, these values are bound between 1 and 1000, while monsters range from 1 to 1500 in almost all cases.

To determine chance to hit, you take the attackers offense, divide it by the defender's defense, and multiply by the chance to hit if the values are equal (currently 60%). So, for example, if the attack's offense is half the defender's defense, the chance to hit is half of 60%, or 30%. The chance to hit is bound between 10 and 95. This means a battler is never unhittable or unmissable, no matter what the values are. It is important to note that this equation makes combat more hit-centric, where it is easier to get skill to hit someone then it is to get the ability to be missed all the time.

Note that these values can be gathered in-game by use of the "evaluate" spell. This DM-only spell will give the combat abilities of any target. This spell should be used sparingly, however, because the side-effects of combat (such as wear and tear on equipment, etc) will happen when the target is evaluated. The effect should be small, but repeated use can cause unwanted effects.

When an attack is made, we start in TryAttack. This is the core message used for combat. If we hit, we call AssessDamage to the target (so that it can record the damage) and AssessHit to self. AssessHit is used by battler for side-effects, like poisoning, etc. If we kill the target, we send KilledSomething to ourselves, otherwise we send DidDamage to ourselves. If we miss, we call AssessMiss to ourself (to see if any catastrophic side-effects happen). We always send SomethingAttacked to our owner for an attack.

The attacker is responsible for miss messages in combat. If the attacker misses, the it queries the defender for the reason of the miss. Right now, defenders can block, parry, dodge or "avoid" (generic catch-all) an attack. The attacker is responsible for hit messages in combat. The defender gives the type of damage it suffered and amount of damage, which the attacker reports in a combat message.

Combat Values for Players

If a player is Morphed, they always use the values of the monster they have morphed into for all combat functions.

A player's offense is calculated from the following equation: (Stroke*3) + (Proficiency*2) + (Aim*4) + (Base Max Health*3/2).

Stroke is the player's percent in the basic skill that governs a weapon's use. This would be slash, punch, or fire, depending on the weapon. This number ranges from 0 to 99.
Proficiency is the player's percent in the advanced skill that governs a weapon's use. This would be scimitar wielding, archery, brawling, mace fighting, etc, depending on weapon. This number ranges from 0 to 99.
Base Max Health is the player's maximum amount of hit points before any modifications (such as from a circlet). This number ranges from 20 to 150.

The attack modifiers a player has will affect this value as well. Spells such as bless, or items such as berzerker rings will increase or decrease this value. The faction bonus and bonuses from the weapon are also calculated in this figure. After all modifiers are applied, the result is bound between 1 and 1000.

If we hit, we poll the stroke for the type of damage we do. If there is no stroke object, then we query the weapon for damage. Note that touch attacks are both stokes and weapons in this case. Attack modifiers and faction bonuses can modify the damage. The base damage never exceeds 10 damage, Might adds (Might-20)/10 damage (minimum of 0), Proficiency (for weapons) adds ((percent+1)/20) damage, and all other bonuses are limited to 7 points of bonus damage. This means that no hit should do more than 25 points of damage.

A player's defense is calculated from the following equation: (Parry*2) + (Block) + (Dodge*3) + (Agility*4) + (Base Max Health*3/2)

Parry, Block, and Dodge are the player's percent in the corresponding skills. Weapons can affect parry (EG, bows return 0 for parry), and shields can affect block, and movement (IE not being held) can affect dodging. The type of blow we're defending against can determine the values, too (e.g., bows cannot be parried). These values range from 0 to 99.
Base Max Health is the player's maximum amount of hit points before any modifications (such as from a circlet). This number ranges from 20 to 150.

The defense modifiers a player has, such as armor, will affect this value, too. Parliament bonuses are also calculated into this figure. After all modifiers are applied, the result is bound between 1 and 1000.

If we are hit, our defense modifiers can reduce damage. Currently, armor is designed to make the player easier to hit (it lowers the Defense value), but it absorbs damage from blows. Resistances also reduce damage depending on damage type.

As a note: The message LookupPlayerWeapon will return the melee weapon the player wields (or $ if they have no melee weapon), where GetWeapon will return the weapon the player is using, including any touch attack spells, or it will return $ if they are using punch.

Combat Values for Monsters

Monsters were changed to be able to define raw offense and defense values, as well as maximum and minimum damage. However, to save the time of retrofitting all the existing monsters, the monsters can use the existing viLevel and viDifficulty values to define the values.

A monster's offense is piOffense, or (3*viLevel) + (60*viDifficulty) if that variable is $.
A monster's defense is piDefense, or (3*viLevel) + (60*viDifficulty) if that variable is $.
A monster's damage is random(piMinDamage,piMaxDamage), or 80-120% of viLevel/Random(10,15) if those values do not make sense (EG, are $, or Min is greater than Max, etc).

The damage value code is a bit unsteady, so it is recommended you do NOT change the values if the monster is in combat. It is also recommended that you pay careful attention to the values, and make sure they make sense (IE, piMinDamage is less than piMaxDamage).

In combat equations, monsters use themselves as stroke objects and weapons. Therefore, when a battler sees if it can dodge a stroke object, it checks that in the monster directly.

Other numbers:
Monsters can see (4 + viDifficulty/2) units away.
Monsters can attack (2 + viDifficulty/6) (either 2 or 3) units away.