The PTR are the Public Test Realms which are a set of realms provided by Carbine for use with publicly testing the next version of WildStar, what ever that is. Accounts will need special invitation or code to be able to participate on the PTRs.
These realms are similar to the other regular game release version realms divided by Account region, such as NA, and EU, and are select-able via the WildStar loader-updater program's configuration menu. Once a game version is released, the normal release realms get updated to that version, and the PTRs will be used to test something else.
- Initial WildStar public beta testing, before the game's first product release, was done on the regular regional release or live game realms. The PTRs were effectively reserved for private internal testing, but were still visible as Region: Test [Locked] on the loader list.