Hack This Site is a free, safe and legal training ground for hackers to test and expand their hacking skills: http://www.hackthissite.org
In this site there are dozens of simulated wargames that allow users to put their skills to the test in a legal, realistic environment. There are several kinds of challenges each demonstrating different kinds of skills.
Before starting to take your first challenge, you have to register. Try to start with the basic web challenge first !
More than just another hacker wargames site, we are a living, breathing community with many active projects in development, with a vast selection of hacking articles and a huge forum where users can discuss hacking, network security, and just about everything. Tune in to the hacker underground and get involved with the project.
In this site there are dozens of simulated wargames that allow users to put their skills to the test in a legal, realistic environment. There are several kinds of challenges each demonstrating different kinds of skills.
Before starting to take your first challenge, you have to register. Try to start with the basic web challenge first !