SECURE MESSAGE RECEIVED from _Unknown_User_:
Probability Grid intercept: 0.9%
We need to act now. You know the Grid has grown in power and reach. There's not a registered CPU remaining it doesn't access. Everything is known, everyone is known. If the Grid isn't burned, it will control everything and our humanity will be lost.
I've got the coordinates. It does have a physical mainframe we can strike, burn every program in it. We can show the world the danger complacency created, that we almost gave up our liberty for convenience.
I've got Drone2004 and E-Terrier ready, but we can't do this without you. We lose, and humanity's freedom is gone. Of course, we do this, we'll be heroes. I figure we've got zero chance anyways, so let's call this Zero Day.
In Zero Day, you are a hacker in a civilization built on technology. Your commensurately useful skill set will allow you to write code or reverse engineer it from ...other sources... and piece it together to find exploits that can be used against the oppressive Mainframe. The first player to inject enough exploits into the Mainframe to bring it under their own control wins — but be warned as the Mainframe will not sit idle when it detects intrusions!
Every round you get three hacker action markers that can be used for one of three things:
Building up programs by "writing" them using appropriate sets of code cubes.
Running your programs to acquire exploit discs.
Reverse engineering other programs by swapping your resources for what's already there (which is also how you inject exploits into the Mainframe).
You may retain action markers from round to round, but they (as well as your unused code and other discs) count against your limited total resource capacity. As a result, you must manage your actions and available space, and balance it with the risk that comes with having programs available to others.