.Hacking

Using the item called Virus Core, players can hack certain areas within the game to give them access to out-of-bounds or system-access areas.

There are two kinds of .hacking (pronounced "dot hacking") using the Virus Core; Gate Hacking, and Sign Hacking.

Sign.Hack
A Sign is a large three-lined image carved into many Lost Grounds and fields. It's not known for sure who made these symbols, but they are not part of the original design of the maps.

Signs lead to various places within The World 2D, but most of them are off-access to regular players, and can normally only be accessed by Admins.

Gate.Hack
Each Root Town contains a Network Gate, which is identified as a small colored symbol implanted somewhere on the ground within the Root Town city limits.

When using a Virus Core within the Root Towns, you are capable of performing Gate Hacking, which will give you temporary Network Access.

This should not be confused with other forms of hacking (such as speed hacks, item duplication, or the /ref hack), which are possible, but are completely illegal to perform. Any form of hacking that attacks the servers host is not allowed.