local combat = createCombatObject()
setCombatParam(combat, COMBAT_PARAM_TYPE, COMBAT_FIREDAMAGE)
setCombatParam(combat, COMBAT_PARAM_EFFECT, CONST_ME_FIREATTACK)

function onGetFormulaValues(cid, level, maglevel)
    min = (maglevel * 3 + level) * 1.2
    max = (maglevel * 3 + level * 2) * 1.3
    return -min, -max
end

setCombatCallback(combat, CALLBACK_PARAM_LEVELMAGICVALUE, "onGetFormulaValues")

local area = createCombatArea(AREA_SQUAREWAVE5, AREADIAGONAL_SQUAREWAVE5)
setCombatArea(combat, area)

function onCastSpell(cid, var)
    return doCombat(cid, combat, var)
end