function CommonFun.calcDamage_20(srcUser, targetUser, params, damageParam, logger)
  local Str = srcUser:GetProperty("Str")
  local Dex = srcUser:GetProperty("Dex")
  local Luk = srcUser:GetProperty("Luk")
  local Atk = srcUser:GetProperty("Atk")
  local AtkPer = srcUser:GetProperty("AtkPer")
  local DamIncrease = srcUser:GetProperty("DamIncrease")
  local IgnoreDef = 0
  local IgnoreDef1 = srcUser:GetProperty("IgnoreDef")
  local IgnoreDef2 = srcUser:GetProperty("IgnoreEquipDef")
  if targetUser.boss or targetUser.mini then
    IgnoreDef = IgnoreDef1
  else
    IgnoreDef = IgnoreDef1 + IgnoreDef2
  end
  if 1 <= IgnoreDef then
    IgnoreDef = 1
  end
  local Refine = srcUser:GetProperty("Refine")
  local Def2 = targetUser:GetProperty("Def")
  local DefPer2 = targetUser:GetProperty("DefPer")
  local Vit2 = targetUser:GetProperty("Vit")
  local VitPer2 = targetUser:GetProperty("VitPer")
  local DamReduc2 = CommonFun.calcDamReDuc(srcUser, targetUser)
  local RefineDamReduc = targetUser:GetProperty("RefineDamReduc")
  local damChangePer = damageParam.damChangePer
  local raceparam = CommonFun.CalcRaceParam(srcUser, targetUser, params, damageParam, logger)
  local bodyparam = CommonFun.CalcBodyParam(srcUser, targetUser, params, damageParam, logger)
  local elementparam = CommonFun.CalcElementParam(srcUser, targetUser, params, damageParam, logger)
  local bossparam = CommonFun.CalcBossParam(srcUser, targetUser, params, damageParam, logger)
  local raceparam2 = CommonFun.CalcRaceParam2(srcUser, targetUser, params, damageParam, logger)
  local bodyparam2 = CommonFun.CalcBodyParam2(srcUser, targetUser, params, damageParam, logger)
  local elementparam2 = CommonFun.CalcElementParam2(srcUser, targetUser, params, damageParam, logger)
  local bossparam2 = CommonFun.CalcBossParam2(srcUser, targetUser, params, damageParam, logger)
  local skillID, skillLevel = CommonFun.UnmergeSkillID(params.skillIDAndLevel)
  if skillID == 380 or skillID == 383 or skillID == 384 then
    AtkPer = 0
  end
  local BaseAtk = Str * 2 + math.floor(Str * Str / 100) + math.floor(Dex / 5) + math.floor(Luk / 5)
  local AtkFinal = ((Atk - BaseAtk) * (1 + AtkPer) * CommonFun.ShapeCorrection(srcUser, targetUser) * bodyparam * elementparam * elementparam2 + BaseAtk) * raceparam * bossparam * bossparam2
  local DefReduc = CommonFun.CalcDef(srcUser, targetUser)
  local ShortRangeDamReduc2 = targetUser:GetProperty("ShortRangeDamReduc")
  local A = (AtkFinal * DefReduc * (1 - DamReduc2) + Refine) * damChangePer * (1 - RefineDamReduc) * (1 + DamIncrease - ShortRangeDamReduc2) - Vit2 * (1 + VitPer2)
  if A <= 1 then
    return 1
  end
  return A
end