RootContest provides a free and legal environment for hackers to test and expand their skills. RootContest simulates the exploitation of genuine network and application layer security vulnerabilities, and allows users to exploit them in an attempt to take control of the 'root' account of the servers they are attacking. The war games provided by RootContest are, and always will be hosted under controlled conditions. This means that each and every server donated to RootContest, has been donated with express permission from the owner for it to be used for the purposes of exploitation.
As a direct result RootContest members do not have to constantly worry about the legal implications their actions may cause, promoting and encouraging the use of free and legal hacker wargames.

Wiki
RootContest wiki. - Box Listing page

Call for Developers
RootContest is recruiting developers and moderators to help maintain the web site, the forums, and administer *nix servers. E-mail: rki at rootcontest.com to obtain information on how to apply or join us at irc.rootcontest.com #rootcontest

Call for Servers
RootContest is searching for volunteers to donate *nix servers to be used as wargame platforms. If you own a *nix server, a virtual private server, or can set one up please contact rki at rootcontest.com to contribute.