PTR has 2 meanings
Public test realm
An acronym that refers to the World of Warcraft game servers that allow players to beta test new expansion pack content before it is released.
We practiced the boss fights on the PTR so we could be the first guild on the realm to beat the dungeons.
|WOW||World of Warcraft|
|BC||The Burning Crusade|
|MOP||Mists of Pandaria|
Online card game and board game players use PTR to mean "player to the right." You're most likely to see this acronym used while discussing online poker, to refer to the player seated to a player's immediate right.
However, other online games also care about the order players are seated in, so you may see PTR used while discussing those games. For example, if an MTG streamer is in the middle of a draft, commenters may speculate about what the PTR and PTL are drafting and how it is influencing the streamer's draft.