In "fire wave.lua" the code is:
local combat = createCombatObject()
setCombatParam(combat, COMBAT_PARAM_TYPE, COMBAT_FIREDAMAGE)
setCombatParam(combat, COMBAT_PARAM_EFFECT, CONST_ME_HITBYFIRE)
setCombatFormula(combat, COMBAT_FORMULA_LEVELMAGIC, -0.8, 0, -1.3, 0)
local area =...