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Lua API for D2 modding toolset

Overview

All scripts are expected to be written using Lua language v5.4.1 and should be placed in Scripts folder. Scripts folder itself should be placed in the game folder.

Currently used scripts and their meanings:

  • settings.lua - mss32 proxy dll settings that changes game rules
  • doppelganger.lua - logic that computes level of doppelganger transform (category L_DOPPELGANGER)
  • transformSelf.lua - computes unit level and determines free attacks to give for transform-self attacks (category L_TRANSFORM_SELF)
  • transformOther.lua - computes unit level for transform-other attacks (category L_TRANSFORM_OTHER)
  • summon.lua - computes summoned unit level for summon attacks (category L_SUMMON)
  • textids.lua - contains interface text mapping for custom functionality
  • getAllTargets.lua - contains selection/attack targeting logic for any/all attack reach
  • getAdjacentTargets.lua - contains selection/attack targeting logic for adjacent/all-adjacent attack reach
  • getSelectedTargetAndAllAdjacentToIt.lua - contains attack targeting logic for selective-cleave attack reach
  • getSelectedTargetAndOneAdjacentToIt.lua - contains attack targeting logic for single selective-cleave attack reach
  • getSelectedTargetAndOneBehindIt.lua - contains attack targeting logic for pierce attack reach
  • getSelectedLineTargets.lua - contains attack targeting logic for wide-cleave attack reach
  • getSelectedColumnTargets.lua - contains attack targeting logic for column attack reach
  • getSelectedArea2x2Targets.lua - contains attack targeting logic for 2x2 area splash attack reach
  • getSelectedTargetAndTwoChainedRandom.lua - contains attack targeting logic for random chain attack reach
  • getSelectedTargetAndOneRandom.lua - contains attack targeting logic for additional random target
  • getWoundedFemaleGreenskinTargets.lua - contains targeting logic that only allows to reach wounded female greenskins
  • Scripts/Modifiers contain custom modifier script examples

API reference

Standalone functions

log

Writes message to luaDebug.log file when debugHooks is set to true in settings.lua.

log('Unit current level:' .. unit.impl.level)
getScenario

Returns current scenario. The function only accessible to scripts where scenario access is appropriate:

  • summon.lua
  • doppelganger.lua
  • transformSelf.lua
  • transformOther.lua
  • drainLevel.lua
  • custom attack reach scripts
  • custom unit modifier script

checkEventCondition has scenario as its argument so getScenario is not bound to it.

getScenario():getUnit(unitId)

Enumerations

Race
Race = { Human, Undead, Heretic, Dwarf, Neutral, Elf }
Subrace
Subrace = { Custom, Human, Undead, Heretic, Dwarf, Neutral, NeutralHuman, NeutralElf, NeutralGreenSkin,
            NeutralDragon, NeutralMarsh, NeutralWater, NeutralBarbarian, NeutralWolf, Elf }
Lord
Lord = { Mage, Warrior, Diplomat }
Terrain
Terrain = { Human, Dwarf, Heretic, Undead, Neutral, Elf }
Ground
Ground = { Plain, Forest, Water, Mountain }
Unit
Unit = { Soldier, Noble, Leader, Summon, Illusion, Guardian }
Leader
Leader = { Fighter, Explorer, Mage, Rod, Noble }
Ability
Ability = { Incorruptible, WeaponMaster, WandScrollUse, WeaponArmorUse, BannerUse, JewelryUse,
            Rod, OrbUse, TalismanUse, TravelItemUse, CriticalHit }
Attack
Attack = { Damage, Drain, Paralyze, Heal, Fear, BoostDamage, Petrify, LowerDamage, LowerInitiative,
           Poison, Frostbite, Revive, DrainOverflow, Cure, Summon, DrainLevel, GiveAttack,
           Doppelganger, TransformSelf, TransformOther, Blister, BestowWards, Shatter }
Source
Source = { Weapon, Mind, Life, Death, Fire, Water, Earth, Air }
Reach
Reach = { All, Any, Adjacent }
Immune
Immune = { NotImmune, Once, Always }
Item
Item = { Armor, Jewel, Weapon, Banner, PotionBoost, PotionHeal, PotionRevive,
         PotionPermanent, Scroll, Wand, Valuable, Orb, Talisman, TravelItem, Special }
Equipment
Equipment = { Banner, Tome, Battle1, Battle2, Artifact1, Artifact2, Boots }
DeathAnimation
DeathAnimation = { Human, Heretic, Dwarf, Undead, Neutral, Dragon, Ghost, Elf }
BattleStatus
BattleStatus = {
    XpCounted,             -- Unit was killed and its experience points were counted
    Dead,                  -- Unit dead
    Paralyze,              -- Unit paralyzed
    Petrify,               -- Unit petrified
    DisableLong,           -- Long disable applied (paralyze, petrify or fear)
    BoostDamageLvl1,       -- 25% boost
    BoostDamageLvl2,       -- 50% boost
    BoostDamageLvl3,       -- 75% boost
    BoostDamageLvl4,       -- 100% boost
    BoostDamageLong,       -- Long damage boost (until battle is over or lower damage applied)
    LowerDamageLvl1,       -- 50% lower damage
    LowerDamageLvl2,       -- 33% lower damage
    LowerDamageLong,       -- Long lower damage (until battle is over or removed)
    LowerInitiative,       -- 50% lower initiative
    LowerInitiativeLong,   -- Long lower initiative
    Poison,                -- Poison dot
    PoisonLong,            -- Long poison applied
    Frostbite,             -- Frostbite dot
    FrostbiteLong,         -- Long frostbite applied
    Blister,               -- Blister dot
    BlisterLong,           -- Long blister applied
    Cured,                 -- Cure applied
    Transform,             -- Unit transformed by another unit
    TransformLong,         -- Long transformation applied by another unit
    TransformSelf,         -- Unit transfomed himself
    TransformDoppelganger, -- Doppelganger transformation
    TransformDrainLevel,   -- Drain level applied
    Summon,                -- Unit was summoned during battle
    Retreated,             -- Unit retreated from battle
    Retreat,               -- Unit is retreating
    Hidden,                -- Unit is hidden. For example, while leader dueling a thief
    Defend,                -- Defend was used in this round
    Unsummoned             -- Unsummon effect applied
}
Relation
Relation = { War, Neutral, Peace }

Point

Represents point in 2D space.

Methods:

-- Creates point with both coordinates set to 0.
Point.new()
-- Creates point with specified coordinates.
-- For example: x = 1, y = 3
Point.new(1, 3)
-- Converts point to string '(x, y)'
tostring(point)
-- Access x coordinate for reading and writing
local x = point.x
point.x = x + 1
-- Access y coordinate for reading and writing
local y = point.y
point.y = y + 1

Id

Represents object identifier. Identifiers used to search scenario objects.

Methods:

-- Creates Id from string
Id.new('S143KC0001')
-- Returns empty identifier
Id.emptyId()
-- Converts Id to string
tostring(id)
-- Returns integer representation of id.
-- Can be used as Lua table key for best performance.
id.value
-- Returns identified object index among the same type of scenario objects (units, stacks, items, etc.).
-- Can be used as Lua table key for best performance.
id.typeIndex

Modifier

Represents unit modifier. Modifiers wrap unit implementation.

Methods:

id

Returns modifier id. MODIF_ID value from Gmodif.dbf.

modifier.id

Unit

Represents game unit that participates in a battle, takes damage and performs attacks. Unit can also be a leader. Leaders are main units in stacks.

Methods:

-- Returns unit's current experience points.
unit.xp
-- Returns unit's current hit points.
unit.hp
-- Returns unit's maximum hit points.
unit.hpMax
id

Returns unit id. This is different to id of unit implementation. The value is unique for every unit on scenario map.

unit.id
impl

Returns unit's current implementation. Current implementation describes unit stats according to its levels and possible transformations applied during battle.

unit.impl
baseImpl

Returns unit's base implementation. Base implementation is a record in GUnits.dbf that describes unit basic stats.

unit.baseImpl
leveledImpl

Returns unit's leveled (generated) implementation. Leveled implementation is unit's current implementation without modifiers, or base implementation plus upgrades from GDynUpgr.dbf according to unit's level. This does not include leader upgrades from GleaUpg.dbf, because the upgrades are modifiers.

unit.leveledImpl
original

Returns original unit dummy that represents unit state before transformation, or nil if unit is not transformed. The state does not include any unit modifiers thus contains only leveled implementation. Unit can be transformed by transform-self, transform-other, drain-level or doppelganger attack.

unit.original
originalModifiers

Returns array of original modifiers that were applied to unit before transformation, or empty array if unit is not transformed. Usually, modifiers are reapplied after transformation, but there are cases where some modifiers are incompatible with a new form, thus not getting applied to it.

unit.originalModifiers

Unit dummy

Represents preserved state of game unit. Used, for instance, to preserve unit state before transformation, so it can be restored later. Methods are identical to unit, except that there is no original and originalModifiers.

Unit implementation

Represents unit template. Records in GUnits.dbf are unit implementations.

How unit implementation works and why it is different to unit

Unit implementation is a unit template that can be used by different individual units on scenario map. It is different to unit, because different unit instances can have the same implementation. For example, you can have 3 Squires of level 1 in your party, each having the same implementation.

There are 3 different stages of unit implementation that build on top of each other:

  • Global, corresponds to a record from GUnits.dbf;
  • Generated, equals Global plus level upgrades from GDynUpgr.dbf (if any);
    • Returned by unit.leveledImpl or impl.generated;
    • Its id is different to id of inherited Global implementation;
    • If unit has no level upgrades, unit.leveledImpl/impl.generated equals unit.baseImpl/impl.global.
  • Modified, equals Generated plus applied modifiers from Gmodif.dbf (if any).
    • Returned by unit.impl;
    • Its id equals to id of inherited Generated implementation;
    • If unit has no modifiers, unit.impl equals unit.leveledImpl/impl.generated.

Unit implementation changes when unit:

  • Gets an upgrade, does not matter if it transforms to higher tier unit or simply gets over-level;
  • Gets transformed: by Transform-Self, Transform-Other, Drain-Level, or Doppelganger attack;
  • Gets modified: when consuming a potion, affected by a spell, equipping an item, getting a leader upgrade, etc.;

Methods:

-- Returns unit's implementation level. LEVEL value from GUnits.dbf.
impl.level
-- Returns experience points needed for next level. XP_NEXT value from GUnits.dbf.
impl.xpNext
-- Returns experience points granted for killing the unit. XP_KILLED value from GUnits.dbf.
impl.xpKilled
-- Returns unit's hit points. HIT_POINT value from GUnits.dbf.
impl.hp
-- Returns unit's armor. ARMOR value from GUnits.dbf.
impl.armor
-- Returns unit's regen. REGEN value from GUnits.dbf.
impl.regen
-- Returns unit's race. ID value from Lrace.dbf. See Race enumeration for all possible values.
impl.race
-- Returns unit's subrace. ID value from LSubRace.dbf. See Subrace enumeration for all possible values.
impl.subrace
-- Indicates if the unit is small (occupies single slot). SIZE_SMALL value from GUnits.dbf.
impl.small
-- Indicates if the unit is male. SEX_M value from GUnits.dbf.
impl.male
-- Indicates if the unit is water only. WATER_ONLY value from GUnits.dbf.
impl.waterOnly
-- Indicates if the unit attacks twice. ATCK_TWICE value from GUnits.dbf.
impl.attacksTwice
-- Returns level after which dynUpgrade2 rules are applied. DYN_UPG_LV from GUnits.dbf.
impl.dynUpgLvl
-- Returns dynamic upgrade 1.
impl.dynUpg1
-- Returns dynamic upgrade 2.
impl.dynUpg2
-- Returns primary attack or nil if no primary attack used.
impl.attack1
-- Returns secondary attack or nil if no secondary attack used.
impl.attack2
-- Returns alternative attack or nil if no alternative attack used.
impl.altAttack
-- Returns leader maximum movement points (or 0 if unit is not a leader).
impl.movement
-- Returns leader scouting range (or 0 if unit is not a leader).
impl.scout
-- Returns current leadership value (or 0 if unit is not a leader).
impl.leadership
id

Returns unit implementation id. UNIT_ID value from GUnits.dbf.

impl.id
base

Returns base unit implementation. BASE_UNIT value from GUnits.dbf.

impl.base
type

Returns unit type.

impl.type
leaderType

Returns leader type (or -1 if unit is not a leader).

impl.leaderType
hasAbility

Returns true if leader has specified ability (or false if unit is not a leader).

impl:hasAbility(Ability.TalismanUse)
hasMoveBonus

Returns true if leader has movement bonus on specified ground (or false if unit is not a leader).

impl:hasMoveBonus(Ground.Water)
global

Returns global unit implementation - a record from GUnits.dbf. Same as unit.baseImpl.

impl.global
generated

Returns generated unit implementation. Equals global plus upgrades from GDynUpgr.dbf according to unit's level. Same as unit.leveledImpl.

impl.generated
modifiers

Returns array of applied modifiers.

impl.modifiers
hasModifier

Returns true if the implementation has modifier specified by id or id string.

impl:hasModifier("G000UM5021")
impl:hasModifier(Id.new("G000UM5021"))
getImmuneToAttackClass

Returns immune type for specified attack type.

impl:getImmuneToAttackClass(Attack.Paralyze)
getImmuneToAttackSource

Returns immune type for specified attack source.

impl:getImmuneToAttackSource(Source.Water)

Unit slot

Represents one of the twelve unit slots on battlefield. Unit positions on a battlefield are mirrored. Frontline positions are even, backline - odd.

1 0    0 1
3 2 vs 2 3
5 4    4 5

Methods:

-- Returns a unit that occupies the slot.
slot.unit
-- Returns a position of the slot (0-5).
slot.position
-- Returns a line index of the slot: 0 - frontline, 1 - backline.
slot.line
-- Returns a column index of the slot: 0 - top, 1 - middle, 2 - bottom.
slot.column
-- Indicates if the slot is on the frontline.
slot.frontline
-- Indicates if the slot is on the backline.
slot.backline
-- Returns a distance between two slots (used for adjacent slot calculations).
slot.distance(otherSlot)

Group

Represents 6 unit slots.

Methods:

id

Returns group id.

group.id
slots

Returns group as array of 6 unit slots.

group.slots
units

Returns group units.

group.units
hasUnit

Returns true if group has specified unit or unit id.

group:hasUnit(unit)
group:hasUnit(Id.new('S143UN0001'))

Fog

Represents player's fog of war.

Methods:

getFog

Returns true if specified map position is covered by fog of war. Map position can be specified by pair of coordinates or a point.

local hidden = fog:getFog(3, 7)

Player

Represents game player including AI and neutrals.

Methods:

id

Returns player id. The value is unique for every player on scenario map.

player.id
race

Returns player race.

player.race
lord

Returns player lord.

player.lord
bank

Returns player bank.

player.bank
human

Returns true if player is human (not AI).

player.human
alwaysAi

Returns true if player is always AI.

player.alwaysAi
fog

Returns player's fog of war. In fully loaded scenario, player objects always have fog of war. During scenario loading this property can return nil.

local fog = player.fog
if fog == nil then
    return
end

Stack

Represents group of 6 unit slots on a map. One of the units is a leader.

Methods:

id

Returns stack id. The value is unique for every stack on scenario map.

stack.id
position

Returns stack position as a point.

stack.position
owner

Returns player that owns the stack. Neutral stacks are owned by neutral player.

stack.owner
inside

Returns fort that this stack is visiting or nil if none.

stack.inside
group

Returns stack units as a group.

stack.group
leader

Returns stack leader unit.

stack.leader
subrace

Returns stack subrace.

stack.subrace
inventory

Returns array of inventory items. This includes equipped items.

stack.inventory
getEquippedItem

Returns equipped item by equipment value.

stack:getEquippedItem(Equipment.Boots)
--- Returns stack current movement points.
stack.movement
--- Returns true if stack is invisible.
stack.invisible
--- Returns number of battles won by the stack.
stack.battlesWon

Fort

Represents Capital or City on a map. Fort contains a garrison group of 6 unit slots. Note that the garrison group is different to a group of visiting stack.

Methods:

id

Returns fort id. The value is unique for every fort on scenario map.

fort.id
position

Returns fort position as a point.

fort.position
owner

Returns player that owns the fort. Neutral forts are owned by neutral player.

fort.owner
group

Returns fort units as a group.

fort.group
visitor

Returns visitor stack, or nil if none.

fort.visitor
subrace

Returns fort subrace.

fort.subrace
inventory

Returns array of inventory items.

fort.inventory
capital

Returns true if fort is a capital city.

fort.capital
tier

Returns fort tier (level). Tiers are in range [1 : 6]. Tier 6 corresponds to the capital city.

fort.tier

Ruin

Represents Ruin on a map. Ruin contains a garrison group of 6 unit slots.

Methods:

id

Returns ruin id. The value is unique for every ruin on scenario map.

ruin.id
position

Returns ruin position as a point.

ruin.position
looter

Returns player that looted the ruin, or nil if none.

ruin.looter
group

Returns ruin units as a group.

ruin.group
item

Returns item reward for looting the ruin.

ruin.item
cash

Returns cash reward for looting the ruin.

ruin.cash

Rod

Represents rod object in scenario. Rods are planted to transform terrain and capture resources.

Methods:

id

Returns rod id. The value is unique for every rod on scenario map.

rod.id
position

Returns copy of rod position as a point.

rod.position
owner

Returns player that planted the rod.

rod.owner

Dynamic upgrade

Represents rules that applied when unit makes its progress gaining levels. Records in GDynUpgr.dbf are dynamic upgrades.

Methods:

-- Returns number of experience points added with each dynamic upgrade. XP_NEXT value from GDynUpgr.dbf.
dynUpgrade.xpNext

Location

Represents location object in scenario.

Methods:

id

Returns location identifier.

location.id
position

Returns copy of location position as a point.

location.position
radius

Returns radius of location

location.radius

ScenarioVariable

Represents scenario variable used by events.

Methods:

-- Returns variable name
variable.name
-- Returns variable value
variable.value

ScenarioVariables

Stores scenario variables, allows searching them by name.

Methods:

getVariable

Searches for ScenarioVariable by its name, reeturns nil if not found.

local variable = variables:getVariable('VAR1')
if (variable == nil) then
    return
end

Tile

Represents map tile.

Methods:

terrain

Returns tile terrain type.

tile.terrain
ground

Returns tile ground type.

tile.ground

Diplomacy

Represents diplomacy relations between races in scenario.

Methods:

getCurrentRelation

Returns current diplomacy relations value between two races in range [0 : 100].

local current = diplomacy:getCurrentRelation(race1, race2)
getPreviousRelation

Returns previous diplomacy relations value between two races in range [0 : 100].

local prev = diplomacy:getPreviousRelation(race1, race2)
getAlliance

Returns true if two races are in alliance.

local allies = diplomacy:getAlliance(race1, race2)
getAllianceTurn

Returns turn number when two races made an alliance. Returns zero if races are not in alliance.

local turn = diplomacy:getAllianceTurn(race1, race2)
getAlwaysAtWar

Returns true if two races are always at war.

local atWar = diplomacy:getAlwaysAtWar(race1, race2)
getAiCouldNotBreakAlliance

Returns true if diplomacy relations prohibit AI-controlled races from breaking alliance.

local couldNotBreak = diplomacy:getAiCouldNotBreakAlliance(race1, race2)
getRelationType

Returns relation type according to diplomacy relations value.

-- Value to type mapping (D_WAR and D_NEUTRAL can be found in GVars.dbf):
-- 0       D_WAR           D_NEUTRAL         100
-- |   War   |     Neutral     |     Peace    |
--
local relation = diplomacy:getRelationType(relationValue)

Scenario

Represents scenario map with all its objects and state.

Methods:

getLocation

Searches for Location by id string or Id, returns nil if not found.

local location = scenario:getLocation('S143LO0001')
if (location == nil) then
    return
end
variables

Returns ScenarioVariables. If scenario has no variables defined, returns nil.

local variables = scenario.variables
if (variables == nil) then
    return
end
getTile

Searches for Tile by pair of coordinates or Point, returns nil if not found.

local tile = scenario:getTile(3, 5)
if (tile == nil) then
    return
end
getStack

Searches for stack by:

  • id string
  • id
  • pair of coordinates
  • point

Returns nil if not found.

local stack = scenario:getStack(10, 15)
if (stack == nil) then
    return
end
getFort

Searches for fort by:

  • id string
  • id
  • pair of coordinates
  • point

Returns nil if not found.

local fort = scenario:getFort(10, 15)
if (fort == nil) then
    return
end
getRuin

Searches for ruin by:

  • id string
  • id
  • pair of coordinates
  • point

Returns nil if not found.

local ruin = scenario:getRuin(10, 15)
if (ruin == nil) then
    return
end
getRod

Searches for rod by:

  • id string
  • id
  • pair of coordinates
  • point

Returns nil if not found.

local rod = scenario:getRod(10, 15)
if (rod == nil) then
    return
end
getPlayer

Searches for player by id string or id, returns nil if not found.

local player = scenario:getPlayer('S143PL0000')
if (player == nil) then
    return
end
getUnit

Searches for unit by id string or unit id, returns nil if not found.

local unit = scenario:getUnit('S143UN0001')
if (unit == nil) then
    return
end
findStackByUnit

Searches for stack that has specified unit among all the stacks in the whole scenario. You can also use unit id string or id. Returns nil if not found.

local stack = scenario:findStackByUnit(unit)
if stack == nil then
    return
end

Note that this search is heavy in terms of performance, so you probably want to minimize excessive calls and use variables to store its results.

findFortByUnit

Searches for fort that has specified unit in its garrison among all the forts in the whole scenario. Only garrison units are counted, visiting stack is ignored. You can also use unit id string or id. Returns nil if not found.

local fort = scenario:findFortByUnit(unit)
if fort == nil then
    return
end

Note that this search is heavy in terms of performance, so you probably want to minimize excessive calls and use variables to store its results.

findRuinByUnit

Searches for ruin that has specified unit among all the ruins in the whole scenario. You can also use unit id string or id. Returns nil if not found.

local ruin = scenario:findRuinByUnit(unit)
if ruin == nil then
    return
end

Note that this search is heavy in terms of performance, so you probably want to minimize excessive calls and use variables to store its results.

day

Returns number of current day in game.

scenario.day
size

Returns scenario map size.

scenario.size
diplomacy

Returns object that holds diplomacy relations between races. Fully loaded scenario always have diplomacy relations. During scenario loading this property can return nil.

local diplomacy = scenario.diplomacy
if diplomacy == nil then
    return
end

Attack

Represents attack of Unit implementation.

Methods:

id

Returns attack id. This is different for every dynamic upgrade unit gets.

attack.id
type

Returns attack type.

attack.type
source

Returns attack source.

attack.source
reach

Returns attack reach.

attack.reach
wards

Returns array of modifiers applied by bestow wards attack.

attack.wards
--- Returns attack initiative value.
attack.initiative
--- Returns attack power (accuracy).
attack.power
--- Returns damage the attack can inflict. Damage depends on attack type.
attack.damage
--- Returns healing the attack can apply. Healing depends on attack type.
attack.heal
--- Returns true if attack has long effect duration. Effect depends on attack type.
attack.infinite
--- Returns true if attack can inflict critical damage.
attack.crit
--- Returns level for boost damage, lower damage and lower initiative attacks.
attack.level
--- Returns true if attack is melee (L_ADJACENT or custom reach marked as MELEE in LAttR.dbf).
attack.melee
--- Returns maximum number of targets (1, 6 or MAX_TARGTS value for custom reach in LAttR.dbf).
attack.maxTargets
--- Returns critical damage percent [0 : 255].
attack.critDamage
--- Returns critical damage chance [0 : 100].
attack.critPower
--- Returns damage ratio [0 : 255] for additional targets.
attack.damageRatio
--- Returns true if damage ratio reapplied for each consecutive target.
attack.damageRatioPerTarget
--- Returns true if damage is split among targets.
attack.damageSplit

Currency

Represents game currency, mana and gold united.

Methods:

new

Creates new currency from existing object.

Currency.new(existing)
infernalMana

Returns or sets amount of infernal mana.

currency.infernalMana
lifeMana

Returns or sets amount of life mana.

currency.lifeMana
deathMana

Returns or sets amount of death mana.

currency.deathMana
runicMana

Returns or sets amount of runic mana.

currency.runicMana
groveMana

Returns or sets amount of grove mana.

currency.groveMana
gold

Returns or sets amount of gold.

currency.gold

Item base

Represents base item of any type (described in GItem.dbf).

Methods:

id

Returns item id. ITEM_ID value from GItem.dbf.

base.id
type

Returns item type.

base.type
value

Returns item value.

base.value
unitImpl

Returns related Unit implementation. For instance: in case of "Angel Orb", Angel unit implementation is returned.

base.unitImpl
attack

Returns Attack that this item performs (in case of orb or talisman), or nil if no attack is associated with the item. For instance: in case of "Orb of Fire", corresponding attack from Gattacks.dbf is returned.

base.attack

Item

Represents item object in the current scenario.

Methods:

id

Returns item id. This is different to id of Item base. The value is unique for every item on scenario map.

item.id
base

Returns Item base.

item.base
sellValue

Returns item sell value, it accounts global sell ratio and used talisman charges (if applicable).

item.sellValue

Battle

Represents battle information.

Methods:

getUnitStatus

Returns whether a unit with a specified id has a specified battle status.

if battle:getUnitStatus(unit.id, BattleStatus.Defend) then
    -- Do something scary
end
currentRound

Returns current round in battle. Round counting starts from 1, but there is a special round 0 when units with 'Doppelganger' attacks present.

battle.currentRound
autoBattle

Returns true if autobattle mode is turned on.

battle.autoBattle
attackerPlayer

Returns player that started battle.

battle.attackerPlayer
defenderPlayer

Returns player that was attacked.

battle.defenderPlayer
attacker

Returns stack that started battle. Only stacks can initiate battles.

battle.attacker
defender

Returns group that was attacked. Defender group can represent units of a stack, fort or ruin. Use group.id to get actual type of a group.

battle.defender

Examples

doppelganger.lua

doppelganger and target have type Unit. item is Item used to perform the attack. battle specifies an information about current battle.

function getLevel(doppelganger, target, item, battle)
    -- Get current doppelganger implementation
    local impl = doppelganger.impl
    -- Get target unit implementation
    local targImpl = target.impl

    -- Get least level value from both
    local level = math.min(impl.level, targImpl.level)

    -- Make sure doppelganger transform level is not lesser than target's base
    local baseImpl = target.baseImpl
    if (level < baseImpl.level) then
        level = baseImpl.level
    end

    return level
end

transformSelf.lua

unit has type Unit. transformImpl is Unit implementation. item is Item used to perform the attack. battle specifies an information about current battle.

function getLevel(unit, transformImpl, item, battle)
    -- Transform into current level or level of resulting unit's template, whichever is bigger.
    return math.max(unit.impl.level, transformImpl.level)
end

transformOther.lua

attacker and target have type Unit. transformImpl is Unit implementation. item is Item used to perform the attack. battle specifies an information about current battle.

function getLevel(attacker, target, transformImpl, item, battle)
    -- transform using target level with a minimum of transform impl level
    return math.max(target.impl.level, transformImpl.level);
end

attacker and target have type Unit. item is Item used to perform the attack. battle specifies an information about current battle.

drainLevel.lua

function getLevel(attacker, target, item, battle)
    -- transform into unit with its level minus 1 and minus attacker over-level
    return math.max(1, target.impl.level - 1 - attacker.impl.level + attacker.baseImpl.level);
end

summon.lua

summoner has type Unit. summonImpl is Unit implementation. item is Item used to perform the attack. battle specifies an information about current battle.

function getLevel(summoner, summonImpl, item, battle)
    -- Use base level of summon if cheap item is used to summon it
    if item and item.base.value.gold < 500 then
        return summonImpl.level
    end

    -- Summon unit with level twice as big as summoner level
    -- or with level of summon implementation, whichever is bigger.
    local impl = summoner.impl
    local summonerLevel = impl.level

    local summonLevel = summonImpl.level

    return math.max(summonerLevel * 2, summonLevel)
end

See Scripts directory for additional examples.

Targeting scripts (custom attack reaches, specified via Globals\LAttR.dbf)

Targeting scripts are used to specify either selection or attack targets of custom attack reach:

  • Selection targets are targets that can be selected (clicked) (specified as SEL_SCRIPT in LAttR.dbf);
  • Attack targets are targets that will be affected by attack (specified as ATT_SCRIPT in LAttR.dbf). For instance, in case of "pierce" attack, you can only click adjacent targets, but the attack will not only affect the selected target but also the one behind it (if any). Thus the "pierce" attack uses getAdjacentTargets.lua as selection script and getSelectedTargetAndOneBehindIt.lua as attack script.

Targeting scripts use uniform getTargets function for both selection and attack scripts with the following arguments:

  • attacker is the unit slot of the attacker unit;
  • selected is the unit slot of the unit that was selected (clicked). selected.position == -1 and selected.unit == nil if this is selection script (no target is clicked yet);
  • allies are unit slots of all the allies on the battlefield (excluding the attacker);
  • targets are unit slots of all the targets on the battlefield on which the attack can be performed. For instance, if targets are allies and the attack is Revive, then it will only include dead allies that can be revived;
  • targetsAreAllies specified whether targets are allies;
  • item specifies an item (orb or talisman) used to perform the attack, or nil if no item is used;
  • battle specifies an information about current battle;
  • isMarking specified whether the script is being called to mark targets visually on the battlefield. Can be used to provide consistent visual representation for randomized scripts, as soft alternative to MRK_TARGTS flag in LAttR.dbf. Always false if this is selection script.

Example of attack script of pierce attack (getSelectedTargetAndOneBehindIt.lua)

function getTargets(attacker, selected, allies, targets, targetsAreAllies, item, battle, isMarking)
    -- Get the selected target and the one behind it (pierce attack)
    local result = {selected}
    for i = 1, #targets do
        local target = targets[i]
        if target.backline and target.position == selected.position + 1 then
            table.insert(result, target)
            break
        end
    end
    return result
end

Event condition examples

Check if all tiles in location have the same terrain (Human)

-- You can use lambda functions freely
local forEachTile = function (location, f)
    local pos = location.position
    -- Use integers for tile coordinates
    local halfR = math.floor(location.radius / 2)
    local startX = pos.x - halfR
    local startY = pos.y - halfR
    local endX = pos.x + halfR
    local endY = pos.y + halfR
    
    for x = startX,endX,1 do
        for y = startY,endY,1 do
            f(x, y)
        end
    end
end

local location = scenario:getLocation('S143LO0000')
if (location == nil) then
    return false
end

local tilesTotal = location.radius * location.radius
local count = 0

forEachTile(location, function (x, y)
    local tile = scenario:getTile(x, y)
    if (tile == nil) then
        return false
    end
    
    if (tile.terrain == Terrain.Human) then
        count = count + 1
    end
end)

return tilesTotal == count

Custom modifiers

Modifiers in the game stack on top of each other, making ordered modifiers chain.
First modifier takes base values from the unit it modifies, next - values modified by the first modifier and so on.
Custom modifiers allow you to modify every stat of unit and its attacks in a single script file with a number of uniform functions.

Most of the custom modifier functions have the following form:

function getSomething(unit, prev)
    if someCondition then
        return modifiedValue
    end

    return prev
end

unit has type Unit. The unit is presented in a state before the current modifier is applied.
prev is a previous value of the stat. It is either a base value or a value modified by the previous modifier.

Check Scripts/Modifiers for script examples.
template.lua contains a complete list of available functions.

Due to how modifiers chain work, you have no direct access to final unit stats

For example:

  • Lets say we have a unit with base of 50 initiative;
  • Then we give it a potion that increases damage by 50% if unit initiative > 60;
  • Then we give it another potion that increases initiative to 70.

The damage bonus will not work in this case, even though a final unit initiative is 70 that is > 60. This is because damage modifier applied earlier than initiative modifier. If we get unit.impl.attack1.initiative from the damage modifier script it will be 50, because initiative modifier is not applied yet.

Dangerous way around to get final unit stats

The limitation described above can be avoided by getting unit instance via getScenario:getUnit(unit.id).
But you have to be very careful using this approach, as you can easily fall into a deadloop.

Lets see a bad example where we created a modifier that grants bonus armor and regen depending on each other:

function getArmor(unit, prev)
    local finalUnit = getScenario():getUnit(unit.id)
    return prev + finalUnit.impl.regen / 5
end

function getRegen(unit, prev)
    local finalUnit = getScenario():getUnit(unit.id)
    return prev + finalUnit.impl.armor / 10
end

Or it can be two different modifiers, does not matter:

-- MyBonusArmorMod.lua
function getArmor(unit, prev)
    local finalUnit = getScenario():getUnit(unit.id)
    return prev + finalUnit.impl.regen / 5
end

and

-- MyBonusRegenMod.lua
function getRegen(unit, prev)
    local finalUnit = getScenario():getUnit(unit.id)
    return prev + finalUnit.impl.armor / 10
end

When this modifier(s) applied to a unit, we are getting circular dependence here: final armor depends on final regen while final regen depends on final armor.
Imagine what happens when the game tries to get unit armor:
It calls getArmor that calls getRegen that calls getArmor that calls getRegen that calls getArmor that calls getRegen that calls getArmor...and so on until your game hang or crash to desktop.

As a good example, you could refer to a third stat, thus avoiding deadloop condition:

-- MyBonusArmorMod.lua
function getArmor(unit, prev)
    local finalUnit = getScenario():getUnit(unit.id)
    return prev + finalUnit.impl.regen / 5
end

and

-- MyBonusRegenMod.lua
function getRegen(unit, prev)
    local finalUnit = getScenario():getUnit(unit.id)
    return prev + finalUnit.impl.level / 10
end

This way, regen depends on level, and armor depends on regen and there is no circular dependence in this case.
Remember that this is subject for all modifiers that can potentially happen to be applied to the same unit.