<https://community.battlefront.com/topic/36404-sc-2-air-defense-cities/>
<http://schema.org/text>
"Question: Should players be able to purchase extra Air Defenses for individual cities? \n \nThis would reflect the fact that some cities had more Anti Aircraft Defenses than other cities. \n \nExample: \n \nAllied player can purchase Air Defense Bonus for London for 250MPP. This would increase the Air Defense rating of London by 1. \n \nMaximum Air Defense Rating of a City could be modified +5 through technology advances and +1 via air defense purchase. \n \nPS: If SC2 adds an intelligence tech I would also add a 20% per tech level that the city receives a +1 AD bonus due to advance warning of the incoming attck. \n \nPS2: The air defense rating of a city should also apply to its adjacent port hex. \n  \n [ July 17, 2003, 12:08 PM: Message edited by: Edwin P. ] \n"
<https://community.battlefront.com/topic/36404-sc-2-air-defense-cities/>