According to the Sins Wiki, the two ways to reliably end pirate attacks are to destroy the pirate base or research "Truce Amongst Rogues". While I know that sending out a larger bounty than your opponents means they are attacked first, it can also happen that I'm still attacked. Is there a way to avoid being attacked at all without destroying the pirates or researching "Truce Amongst Rogues" (if you're not a TEC rebel)?
How to reliably avoid pirates
sins-of-a-solar-empire
Best Answer
The wiki is correct. Those two are the only ways to avoid being attacked by Pirates.
However, usually you can guess which system will be the target of the pirates and set up defenses accordingly by buliding a starbase, adding static defenses, and/or moving your fleet into position.
The only time you'll be attacked when you aren't the highest bounty is if they just happen to be moving through your terriotry and your fleet is close enough to engage them. They will take potshots at you as they pass through.