Public Test Realm

A Public Test Realm (PTR) is a special server used for testing upcoming content. Similar to an open beta test, a PTR helps to test for bugs, gather feedback and fine-tune game balance.

Hearthstone does not currently use a PTR, but evidence first noted in 2016 suggests that one may be planned for the future.

In Hearthstone
While commonly used for Blizzard games such as World of Warcraft, Heroes of the Storm, and , Hearthstone has traditionally not used a PTR, with the developers instead choosing to focus on internal testing - both among the development team and among the wider pool of other Blizzard staff - to explore and refine their ideas. The developers have previously stated that one reason was that a PTR would require making each new set of cards available to players for at least a month prior to their actual release, causing content to age more rapidly and the new meta to be "solved" sooner, possibly even before release.

In mid-July 2016, evidence of a Hearthstone PTR began to appear. On July 19 Hearthpwn.com noticed a new build that included encrypted data for a PTR. Reports surfaced a few days later of an option during the card pack code redemption process, which allowed players to select a "Public Test Realm (PTR)" as the target server for their card pack, alongside the regional Americas, Europe and Asia servers.

Given the developers' stance regarding PTRs, internal testing and wanting to avoid spoiling cards in advance, it is possible the PTR may be intended exclusively for testing new features or changes to the client, in order to avoid bugs and server difficulties when the content goes live.