Explain IADS placement.

2.3-Campaign-Design.md

@@ -148,4 +148,21 @@ To define a potential ship location place a CJTF Blue Arleigh Burke IIa.
 
 Missile sites (scuds, V-2s, etc) can be generated at airbases. Missile sites will only be spawned if the faction has them defined, and the amount is randomly selected between 0 and the limit defined by the faction. There is no limit on how many can be spawned as is it is up to the faction designer, so place as can sensibly be placed (a dozen should be more than enough, and five should be plenty).
 
-Missile sites are currently only generated randomly. TODO: Fix.
+Missile sites are currently only generated randomly. TODO: Fix.
+
+### IADS
+
+To guarantee that each faction begins with a strong IADS, SAMs can be forced to spawn at specific locations. These will take the place of the randomly generated SAM objectives when they exist, but are not required. They are strongly recommended as random SAM placement will lead to more easily defeated air defenses.
+
+Required SAM locations are automatically associated with the control point closest to them.
+
+To define a require SAM location, place a CJTF **Red** unit of any of the following types:
+
+* SAM Hawk LN M192
+* SAM Patriot LN M901
+* SAM SA-10 S-300PS LN 5P85C
+* SAM SA-10 S-300PS LN 5P85D
+* SAM SA-2 LN SM-90
+* SAM SA-3 S-125 LN 5P73
+
+Note that the exact type of SAM that will be placed depends on the faction data. However, when designing a campaign with specific factions in mind (such as Syria defending on the Syria map), this allows the designer to see the coverage of the SAMs used by the intended faction. This way the designer can be sure that sufficient coverage will be present in the campaign when a faction using a specific type of SAM is used.