special-attacks.rst

lua

lua

Rules

Special Attacks

SpecialAttack

Table interface for special attacks. All fields are optional.

Fields:

ab : function or int

Determines attack bonus modifier. If this field is a integer that value is returned for every special attack. If it is a function it must satisfy the same function signature as GetSpecialAttackModifier

damage : function or DamageRoll

Determines damage modifier. If the value is a DamageRoll that value is returned for every special attack. If it is a function it must satisfy the same function signature as GetSpecialAttackDamage

impact : function

Determines if a special attack is successful and optionally any effect(s) to be applied. The function, if any, must satisfy the same function signature as GetSpecialAttackImpact. Its boolean return value indicates whether a special attack was successful or not, false or nil indicates the target has resisted the attack.

If no function is set, the special attack is always successful.

use : function

Determines if a special attack is useable. The function will be called with the following parameters: special attack type, attacker, target and it must return true or false. Note: the function is responsible for providing any feedback to the player.

GetSpecialAttackDamage(special_attack, info, attacker, target)

Determine special attack damage. Should only every be called from a combat engine.

param int special_attack

SPECIAL_ATTACK*

param info

Attack ctype from combat engine.

param attacker

Attacking creature.

type attacker

Creature

param target

Attacked creature.

type target

Creature

rtype

DamageRoll

GetSpecialAttackImpact(special_attack, info, attacker, target)

Determine special attack effect. Should only every be called from a combat engine.

Note

The boolean return value indicates whether the special attack was successful.

param int special_attack

FEAT* or SPECIAL_ATTACK*

param info

Attack ctype from combat engine.

param attacker

Attacking creature.

type attacker

Creature

param target

Attacked creature.

type target

Creature

rtype

boolean and optionally an Effect or an array of Effect.

GetSpecialAttackModifier(special_attack, info, attacker, target)

Determine special attack bonus modifier. Should only every be called from a combat engine.

param int special_attack

SPECIAL_ATTACK*

param info

Attack ctype from combat engine.

param attacker

Attacking creature.

type attacker

Creature

param target

Attacked creature.

type target

Creature

rtype

int

RegisterSpecialAttack(special_attack, ...)

Register special attack handlers.

The vararg parameter(s) can be any usable feat, it is not limited to hard-coded special attacks. When a special attack is registered, a use feat event handler is also registered; it will handle adding the special attack action, will override any other uses of the feat, and any feedback messages like *Special Attack Resisted* floating strings.

param special_attack

See the SpecialAttack interface.

param ...

FEAT* or SPECIAL_ATTACK* constants.

Example

local Eff = require 'solstice.effect'
local Attack = require 'solstice.attack'
local GetAttackRoll = Attack.GetAttackRoll

local function kd_use(id, attacker, target)
  if Rules.GetIsRangedWeapon(attacker:GetItemInSlot(INVENTORY_SLOT_RIGHTHAND)) then
    if attacker:GetIsPC() then
      -- Normally for these hardcoded feats a localized string would be sent,
      -- but this is just an example.
      attacker:SendMessage("You can not use Knockdown with ranged weapons.")
    end
    return false
  end
  return true
end

local function kd_impact(id, info, attacker, target)
  local size_bonus = id == SPECIAL_ATTACK_KNOCKDOWN_IMPROVED and 1 or 0
  if target:GetSize() > attacker:GetSize() + size_bonus then return false end

  if GetAttackRoll(info) > target:GetSkillRank(SKILL_DISCIPLINE) then
     local eff = Eff.Knockdown()
     eff:SetDurationType(DURATION_TYPE_TEMPORARY)
     eff:SetDuration(6)
     return true, eff
  end

  return false
end

Rules.RegisterSpecialAttack({ use = kd_use, impact = kd_impact, ab = -4},
                            SPECIAL_ATTACK_KNOCKDOWN_IMPROVED,
                            SPECIAL_ATTACK_KNOCKDOWN)