EMP weapons in Command and Conquer 3: Tiberium Wars were somewhat of a finesse tactic that were largely ignored by the majority of players (the EMP Control Center was the 2nd least captured building after the Mutant Hovel). They were often reserved for the more skilled players who used a well placed Shockwave Artillery to disable a horde of Avatars - much to the disbelief of the Avatar's owner.
Refreshingly, Command and Conquer 3: Kane's Wrath has a plethora of new EMP weapons (even granting them to one faction at tier 1) in combination with the changes to harvester health, blue tiberium in Ranked Maps and the incorporation of new "Epic Units." Flattening your enemy's giant army with your own giant army isn't always going to be viable, and is far from being the smartest option. That's where EMP weapons come in. Using EMP weapons can enable you to disable your enemy's army thus leaving them as sitting ducks to be mopped up by the rest of your army.
EMP weapons play a much more important purpose in Kane's Wrath than they did in Tiberium Wars and the above use is one of the multitude of different uses for EMP weapons.
EMP Abilities In Kane's Wrath
EMP Control Center The EMP Control Center is practically unchanged from Tiberium Wars. This neutral tech structure is found on certain maps such as Tournament Decision and can be captured with an Engineer/Saboteur/Assimilator. After 3 minutes this EMP power will be available for your use.
For Information on EMP Control Center, check out this Tiberium Wars TotW.GDI EMP Abilities
Grenadier Squad
The GDI Grenadier is no longer just a garrison clearer in Kane's Wrath - it can now be equipped with EMP Grenades from the Armory for just $1000. Firstly, its a unit activated ability so you can't just stick them in a Hammerhead and rain EMP Grenades from the sky, so you will have to have the Grenadier out of any garrison to use the ability.
A good plan would be to use APCs or Hammerheads to quickly transport a squad of EMP equipped Grenadiers to a suitable bottleneck ahead of your main army, then disable your enemy's army (with a good hot-key set up you should be able to use several squad's EMP Abilities almost instantly and as a result deliver an effective blow to your enemy). Then send your main force in to deliver the first strike. Since the Armory is not available for the Steel Talons sub-faction, they can not make use of the EMP Grenades upgrade.
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GDI's Shockwave Artillery is unchanged and available for use as soon as the Space Command Uplink is constructed. One of the main limitations of this is that it does take a few seconds to impact the location and its distinctive firing sound can give it away.
Hence it's not the best option for hitting moving targets and as a result it's best used on stationary units or structures - when in the middle of a large battle where units are unlikely to move much. Though, it is best used for bases (as the EMP shells cant be prevented from impacting) instead of against units.
