In their first ever producer letter, newly hired TERA project manager Noesis revealed plans for a temporary test server designed to try out new rulesets and events. The server is named Wonderholme and will be a way for the devs to experiment with the help of players while stress testing almost everything.
It should be noted that players will not be able to transfer characters to or from Wonderholme. In fact there will be frequent wipes. So go in with the mindset of not worrying about progress.
In addition to the server, the letter also discusses an upcoming content update and the game’s 5th anniversary. You can read the letter in full on the TERA site.