function gadget:UnitPreDamaged(unitID, unitDefID, unitTeam, damage, paralyzer,
                            weaponID, attackerID, attackerDefID, attackerTeam)
  if (attackerDefID and
      UnitDefs[attackerDefID].customParams and
      UnitDefs[attackerDefID].customParams.nofriendlyfire and
      attackerID ~= unitID and
      spAreTeamsAllied(unitTeam, attackerTeam)) then
	return 0
  end
  return damage
end