Add a subrule to “Corporate Defence” called “Security”:

A Corp Name may have zero or more Security Measures, tracked as non-numeral characters in the Corp Name’s “Tool” field.

At any time, a Hacker may reduce its Corp Name’s Defence Score or Secrets by 1 to add any Security Measure to that Corp Name.

Valid Security Measures and their effects are:

• | - Firewall - Each Firewall a Corp Name has negates the rightmost Subroutine in the Hack Tool of any Codename which makes a Hack against that Corp Name.
• @ - Honeypot - Each Honeypot a Corp Name has negates the leftmost Subroutine in the Hack Tool of any Codename which makes a Hack against that Corp Name.
• ) - Shield - Adds +1 to the Defence Score of this Corp Name.