The Ion Cannon provides a colony with the ability to destroy or damage anything hostile destined for the owner or anything owned by your alliance. They are mainly used as defensive tools but may be used in offence if a rare situation arises.
Ion Cannon Uses
Defending Against Incoming Squads
The Ion Cannon, when fired on a group of squads will randomly select one squad, delay that squad by 1 tick and will lower the HP of all the units in the squad to 1.
Defending Against Incoming Missiles/Dragons
Ion Cannons may be used to destroy nukes/dragons, either sitting on their silo/lair or incoming to an OP.
Keep in mind this does not add to the achievement "Shoot down 50 nukes/dragons" So if you are achievement hunting, it wont work that way.
Damaging Units Sitting on OP's/Colonies
Firing the Ion Cannon on colonies or outposts will select 10 random units stationed inside the target and lower their HP 1. This is rarely used due to the high cost and low effect, although the rare occasion comes up every now and then where this tactic is used.
Building an Ion Cannon
Firing the Ion Cannon
1. Select any non-allied squad, nuclear missile, colony, or outpost that fits the criteria below by clicking on it
2. Click the button at the top of the squad to fire the Ion Cannon at it
3. Click on the Events menu to view the post-action report
* Note: If multiple squads are traveling at the same time on top of each other and are targeted by the Ion Cannon, a random squad is chosen to be the target of the Ion Cannon.
Important things to remember!
The Ion Cannon can only be fired on attacking squads which are targeting an OP/Colony which is owned by your alliance
The Ion Cannon can only be fired on missiles/dragons which are targeting an OP/Colony which is owned a by your alliance
The Ion Cannon can be fired on any un-allied missile silos