Kaivax posted that rank 3 will be the cap for phase 1 (level 25). Looks like they will increase through each phase and start at rank 9 when level 60 is first opened up.

 Blizzard Entertainment

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To answer a question we’ve seen from players who are planning to focus on ranking up in Season of Discovery — we’re adding caps to the rank you can achieve during each phase. We want to enable everyone to push rank at a reasonable pace without worrying about rushing to earn highly lucrative PvP rewards.

To start in the first phase of Season of Discovery, at level 25, the cap will be rank 3. Our current plan is to then increase the cap with each new phase, so that rank will cap at 9 for the first few weeks of level 60. Thereafter, we’re planning to increase the rank cap every few weeks along with the release of level 60 content such as Blackwing Lair, finally reaching rank 14 with the opening of The Temple of Ahn’Qiraj.

We’re looking forward to seeing the PvP action in Season of Discovery!

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