In a developer watercooler blog post on Battle.net titled "Raiding Azeroth Part 1-A Look Back," Blizzard begins chronicling the evolution of its raid design philosophy throughout World of Warcraft's decade-long history .
The three-part blog series serves to put the raid changes included in the upcoming Warlords of Draenor patch into proper context. The trilogy of posts retraces raid design changes from Molten Core through Siege of Orgrimmar and explains why Blizzard implemented the changes.
Part one begins at the launch of WoW, where it had two formal raid zones: Onyxia's Lair and the 10-boss Molten Core. At launch WoW's maximum group size was set at 40-player, the pace of leveling was slower than today's standards and the primary goal for majority of players was to reach max level.
The first raid changes were introduced with The Burning Crusade. Maximum size of raids went from 40 to 25 players to improve the gameplay experience for raid groups and to make raiding more accessible "in terms of logistics and the requisite social structures." While Wrath of the Lich King brought "major innovation and fundamental shift to the raiding landscape' and molded the structure recognizable to most WoW players today.
The post also discusses the patches Trial of the Crusader, Ulduar, Naxxramas, Obsidian Sanctum, and Eye of Eternity and Icecrown Citadel the raiding tweaks they each introduced. Part one of the history of WoW raiding system changes can be read in full on the Raiding Azeroth Part 1-A Look Back blog post. The second installment of the blog series will cover present-day raiding and will also trace the evolution of raid systems from Cataclysm through Mists of Pandaria.