Table of Contents
This is a mechanic that has been in the game, but I don't believe many people are necessarily aware of, as I wasn't until today.
How Does Support Defense Work
To begin, we should discuss how Support Defense normally works. A MS with Support Defense can take the hit for an ally that is within its MOV range from where it is currently positioned. This will use a Support Defense token, but the token will not be consumed if the MS conducting the Support Defense successfully evades the enemy attack.
This mechanic works the same for both the player and the AI.
Blocking Support Defenses
Support Defense, when activated, shows an animation of the sprite of the Support Defender moving over to the target that will be Defended.
However, when this is taken into account, the Defender must still be actually capable of reaching the Defense Target within its MOV, taking into account obstacles.
Enemies cannot pass on or through tiles in which your MS are occupying, which means that you can physically body-block their Support Defenders from being able to Support Defend if you physically cut them off by causing the shortest viable path from the Defender to the Defense Target to exceed the Defender's actual MOV value.
Example
To display how this works, I'm going to use GQuuuuuuX and Shin Matsunaga, a Defense Pilot, and Gundam (EX) and Amuro, another Defense Pilot
GQuuuuuuX has a MOV value of 5, meaning that it can Support Defense anyone it can reach within 5 spaces. Meanwhile, Gundam (EX) only has a MOV value of 4, meaning it can only Support Defense anyone within 4 spaces.
Intercepting Support Defense
Here, Gundam EX is 3 tiles away from Dozle Zabi's Zaku II. However, Gundam EX is unable to conduct a Support Defense, as the enemy Gundam has physically blocked the 3 tile path from our Gundam (EX) and Dozle Zabi's Zaku II. The next closest path that our Gundam EX can take is 5 tiles long, which exceeds his MOV value of 4.
In the same 3 tile distance scenario, our GQuuuuuuX can still conduct a Support Defense even though the direct line has been physically obstructed by the enemy Gundam, because unlike Gundam EX, GQuuuuuuX has 5 MOV, meaning that the 5 tile path that takes us around the enemy Gundam to Dozle Zabi's Zaku II is still a valid Support Defense path.
However, by extending the distance between GQuuuuuuX and Dozle Zabi's Zaku II to 4 tiles, the enemy Gundam is able to prevent our Support Defense by standing in the direct column between our two MS, because the next possible path requires GQuuuuuuX to travel 6 tiles, which it cannot.
