Although the GSA is very versatile, it's main strength lies in its defensive capabilities. The focus lies on players who like to be on the defense, waiting for their opponent to come to them and then crush 'em. As evidenced by the multitude of defense and supplement cards, like the Mobile Walls and the Downpour, this is rather easily achieved. Mobility is also being accounted for in the form of various transport cards like the APC and Gunhawk, making movement across the battlefield a breeze. Below you'll find explanations and examples of typical GSA gameplay.
Because of the vulnerability of settlements, along with its strategic value, it would be a good idea to make some
sort of fortification to help defend it. The Mobile Wall card adds 25 DP to your settlement and along with the Downpour
card, which can shoot for 25 AP, make for a fine reinforcement.
A well placed Mine card can also help you take out some of your enemy's cards. The downside to this is that placing
it under your settlement would make it blow your own stuff up when an enemy triggers it, so you'd best keep it in a
surrounding space. Optionally you can keep a Ranger Squad card hidden to have an extra layer of defense.
The Ranger Squad card itself is very useful as its special ability allows it to become hidden, thus giving it the element of surprise and with it, you may catch your opponent off guard. The downside is that it can't move while hidden, so you might want to plan ahead accordingly. The Armadillo card can shoot into a surrounding space, and combined with its 2 space movement , allows for a hit and run type of tactic.
It might be a good idea to grab a unit with a transport special ability, like the APC or the Gunhawk, to speed up your Engineers'
The dilemma with this is wether you want to get your settlement as quickly as possible, to maximize credit gain in the short
run but leave it vulnerable until you are able to draw cards to fortify it, or to wait until you have a stack capable of
supporting your settlement and secure a long term credit flow.
How you deal with this, and any other vital decisions, is up to you.