62015 — Season

The old mastery system was overhauled to include powerful "Keystones," such as Thunderlord’s Decree and Grasp of the Undying , which significantly impacted champion power spikes. 2. Major Features and Innovations

The transition began on , with the rollout of the Season 6 Preseason (Patches 5.22 through 5.24). This period focused on diversifying gameplay through massive updates: Season 62015

It allowed players to queue up with any number of friends (1, 2, 3, 4, or 5) in a single ranked ladder. The old mastery system was overhauled to include