Valley
The Strogg are using a contaminator device to infect the region's water supply. The GDF must destroy it, or let the Strogg turn the local population intro mindless zombies.
Objective: A GDF Engineer must construct the bridge.
The bridge is located just north of the GDF base. Both sides have plenty of vehicles to attack and defense creating an explosive battle at the objective point. A GDF Engineer will be required to construct the bridge; there's also an adjacent optional guard tower objective that can provide additional firepower against the Strogg advance. GDF Medics should be near engineers at the objective point to drop medpacks and supply crates for support. Deploy an artillery interceptor turret to protect against Strogg bombardment.
Strogg defenders should focus attacks on the objective point and heavy GDF vehicle support. Eliminate any GDF radar or artillery interceptor turrets to allow oppressors to target the objective with long-range fire support. Strogg players can mix up their approach to the objective by moving around the bridge to attack from the sides.
Objective: Any GDF class must drive the MCP to the outpost and deploy it.
The MCP appears once a GDF Engineer completes both stages of the bridge construction. Any class can drive the MCP (which also features a minigun for defense). Follow the marked route through the tunnel toward the outpost toward the northwest. Send escort vehicles through the tunnel first to clear out Strogg ground troops. GDF players should also capture and hold the tunnel spawn here to avoid starting back near the bridge upon death. GDF Engineers will be required to repair the MCP if needed to keep it moving toward the outpost target.
Strogg should set up anti-vehicle turrets between the tunnel exit and outpost. Use an artillery interceptor turret to combat GDF Field Ops attempting to bombard the Strogg defenses. GDF Soldiers can exit the tunnel spawn around the left side and target Strogg defenses from long-range with the rocket launcher. A couple anti-vehicle turrets are enough to stop the MCP; they must be disabled by weapons fire, bombardment, EMP grenade, or hack for the MCP to reach the outpost.
Objective: A GDF Covert Ops must hack the Strogg shield generator.
The MCP fires an SMM but the Strogg shield generator blocks the missile. GDF now spawns at the outpost but can gain further ground toward the shield generator by capturing the reservoir spawn point over the bridge. A GDF Engineer can construct a guard tower at the bridge for experience and to provide extra firepower in defending GDF troops and the spawn point. GDF Field Ops should deploy artillery to bombard Strogg defenses around the shield generator to help clear a way for the covert ops to complete the objective.
Strogg defenders should deploy anti-vehicle turrets between the bridge and generator and anti-personnel turrets closer to the generator to target approaching GDF Covert Ops. Also use an artillery interceptor turret to guard against GDF Field Ops long-range bombardment. Strogg Constructors will need to maintain repairs on these turrets for adequate defense. Both sides have plenty of vehicles creating another huge battle around the shield generator.
Objective: A GDF Soldier must destroy the Strogg Contaminator.
Successfully hacking the shield generator allows the MCP to launch the SSM, which strikes the building holding the contaminator. It's just southeast of the shield generator. A GDF Soldier must reach the contaminator and plant and arm an HE Charge to destroy the device and complete the objective. After planting the explosive, remain in the area to counter any Strogg Constructors attempting to disarm the explosive.
Volcano
The GDF are using an outlying geothermal facility to create an atmospheric EMP weapon with which to drive the Strogg out of Earth's orbit and halt the invasion. The Strogg must destroy the geothermal energy core to prevent the GDF from disabling their fleet.
Objective: A Strogg Infiltrator must hack the security controls.
Strogg attackers begin on the southern edge of the beach; the targets lie inside the well-foritified GDF base on the northern side. Strogg players can use various debris and walls as cover against GDF snipers. Immediately advance to the beach head spawn point located on the eastern edge of the beach north from the original Strogg spawn point. A Strogg Constructor should deploy an artillery interceptor turret to avoid frequent GDF bombardment along the beach.
There are multiple ways to breach the GDF base. A Strogg Aggressor can plant and arm a plasma charge on the forward bunker door (located in the middle, due north from the Strogg spawn), seawall breach (just west of the forward bunker door and best route to the transformer objective), and the east bunker breach (positioned east of the forward bunker door and contains vents infiltrators can teleporter into and sneak into the control room). All of these optional tasks reward experience and provide new access points for all mission tasks. A Strogg teammate with vehicle experience can call an Icarus, which provides an easy method of moving into GDF territory.
Strogg Infiltrators need not worry about these breach points: the infiltrator's teleporter can be shot over the walls to quickly gain access to the objective area. Fire the teleporter and hit the fire button again to teleport; use the alternate fire button to reset the teleporter if you missed your mark. An infiltrator can use the teleporter to quickly liberate the GDF's forward spawn at the bunker building, which will greatly slow GDF defense. Gain a disguise and check the GDF defenses around the controls or start backstabbing the enemy. Once a Strogg Infiltrator successfully hacks the ssecurity controls, the next objective begins.
Objective: A Strogg Aggressor must destroy the transformer.
The transformer is located in a building on the western side of the base. Moving through the seawall breach is the fastest route to the building. GDF defenders should attempt to slow down the Strogg exterior advance with turret defenses. Don't forget to have radar up and away from possible Strong counterattack.
There are multiple routes into the building itself; a back entrance that the GDF will generally use provides faster access to the transformer room. Strogg must work in groups to push GDF defenders down into the transformer room where they can be picked off from the higher catwalks. Technicians should create spawn hosts so Strogg teammates don't have to make the long trek back from the spawn position. Beware of engineer mines throughout the halls and around the transformer. A Strogg Aggressor must plant and arm a plasma charge on the transformer. Take cover inside the room and eliminate any GDF counters, specifically the engineer who can defuse the charge.
Objective: Strogg Infiltrators must fly their flyer drones through the access vents and destroy the energy core.
Destroying the transformer opens a route into the geothermal energy core, located on the northern side of the base. To complete the final objectives, the Strogg Infiltrators must use their flying drones to bombard the energy core. Five drones must strike the core; the energy core begins at 100% and each hit from the drone brings it down 20%. Each time a drone strikes the core, the percentage is revealed so you know exactly how many more hits you need.
From the main entrance, use the entrances on the bottom level to locate the vents. Fly a drone into the vent and follow to the energy core; detonate the drone on the core to inflict damage. Flying drones only last 30 seconds before they are deactivated. It's possible, though time critical, to keep the infiltrator back and away from GDF defenses while moving the drone through the main room and into the vents. The mission ends in a Strogg victory once five infiltrator drones explode next to the core.