Raid design has changed more times than there have been actual expansions in World of Warcraft, mostly because original raiding concepts were forged in the endgames of EverQuest, Dark Age of Camelot, and the pre-WoW generation of MMOs. Patch 1.11.0 introduced Naxxramas, one of the most ambitious raid environments in the history of WoW. The massive necropolis floated ominously above the Eastern Plaguelands, tempting the best raiding guilds with 15 punishing boss encounters. Naxxramas was ultimately removed from the game with patch 3.0.2, when it was replaced with new 10- and 25-man versions of Naxxramas retuned and reitemized as the starter raid for Wrath of the Lich King. The retuning of Naxxramas is one of the best examples of the changing raid dynamics from the original vanilla WoW to the new Wrath dynamic.
Back in the original Naxxramas days, raids were tuned for 40 players. Half of the challenge of raiding in the old days was putting the raid together in the first place, and then actually getting boss strategies down. There was even an attunement to Naxxramas based on your Argent Dawn reputation, which scaled in price depending on how close to exalted you were. Suffice it to say, it was a very different world. Naxxramas' difficulty at the outset was the hardest dungeon WoW had ever seen, and in consequence, not many raid groups got to see the inside of Naxxramas, much less its final encounters.
Over time, the raiding dynamic greatly changed and 10- and 25-man encounters were the new norm. The huge success of Karazhan made 10-man raiding a staple in future WoW expansions. When Naxxramas was poised to make its return as the beginning raid in Wrath of the Lich King, people wondered how certain encounters (which were built for 40-man raid groups consisting of upwards of six tanks on some fights) would be rebuilt for 10- and 25-man raiding groups. Many people didn't think that the flavor and epicness of the instance would stay intact.
Back when I did the original Anub'Rekhan fight, I was a healer who had tank-specific healing duties as well as trying my best not to get hit by spikes and baby spider adds all over the place. The retuned Anub'Rekhan was a different story, as I was tanking at the time and had a new set of responsibilities. For everything that changed about Anub, more things stayed the same.
Most of the fight was kind of the same thing as before. The original fight had tighter add control than the revamped encounter, but the real change was the execution-heavy Locust Swarm that required a hunter and warrior team to pull off correctly. In the 40-man version, the kite was essential -- one wrong move and you were walking back. A hunter would pop Aspect of the Pack, staying ahead of his tank while moving in a semi-circle around the acid pools to the sides of the encounter room. Anub was only slowed by 40% of his speed on the 40-man version, and the tank (who was always a warrior) could not use any of his abilities if he was caught in the swarm. The fight would resume after the kite and would repeat every time Anub'Rekhan cast Locust Swarm. For the coordination-impaired, it was a tough feat.
The 10- and 25-man versions of the encounter changed Locust Swarm to a 75% speed debuff, removing the need for a hunter to be present at all. The raid design philosophy was less about assuming that every raid had a capable hunter, but rather about giving the classes that showed up to the fight the tools necessary and the chance to execute as needed to see the fight completed. The hunter aspect of the fight was built in to the encounter, not the other way around (where players had to bring the buff). This design philosophy has stayed with Blizzard since the revamp to Naxxramas, and you see this sort of thing all over the place now.
The downside to the Locust Swarm nerf was actually the fact that, with good healers, even when the instance relaunched in Wrath, you could just ignore the swarm altogether. Pop some cooldowns, get a little extra healing, and your tank didn't need to kite at all. Potentially mis-tuned? Maybe. But for a raid that was supposed to be the beginner's tier, a complicated boss kite for new tanks at the beginning of a raid wing is not the first thing I would throw at players.
Heigan has always been a fan favorite encounter in Naxxramas because of the infamous Heigan Dance. Have you ever had to do the Heigan Dance? You might want to check out the video above for some old-school tips.
The irony of the video is that the encounter did not change substantially from the original. With player fears on the rise that the new Naxxramas would be a shell of its former self, Heigan's dance was in the crosshairs of player worriment. The infamous 1-2-3-4-3-2-1 dance was unchanged, but the encounter did receive a tweak or two. The entire eye stalk tunnel teleport was removed in favor of a simplified fight design that focused on the real meat of the encounter -- the dance. Blizzard wanted to streamline the fight, and the weird eye stalk room was something that just added complexity to an otherwise fun encounter. Heigan was not meant to be impossible but rather to be a teaching moment for all players about movement-based encounters.
If you knew what you were doing, Heigan was a fight where practically all of the damage was mitigatable by the players. Looking forward, heroic Ragnaros and other fights would use the Heigan model, as well as the entire DPS philosophy of Cataclysm, where personal responsibility for mitigating and avoiding damage was the norm. In its original and revamped formats, Heigan and his dance were the beginnings of this new outlook.
Loatheb was one of the most unique fights in the original Naxxramas and one of the encounters most changed by the Naxxramas revamp. The fight was a punishing DPS race that relied on excellent healers and a deep understanding of the mechanics in order to pull it off correctly. In the original encounter, healers were only allowed to cast one beneficial spell every minute, including dispels like removing poisons or Cleanse. You could not stack healers, as the DPS requirements for the fight made it absolutely necessary to keep lots of damage on Loatheb at all times. In order to assist with damage, the Fungal Bloom buff from killing spores would increase your critical strike change by 50%. Player personal responsibility for using cooldowns and consumables was paramount to beating the encounter.
For the new Loatheb, the one-heal-per-minute design was changed completely. Instead, Loatheb now would cast a debuff called Necrotic Aura, reducing all healing spells' effectiveness by 100%, lasting for 17 seconds. After the debuff dropped, healers had 3 seconds to use all the healing spells they could to keep the raid alive and top the tank off. This mechanic change was much easier to explain and deal with, giving healers a little wiggle room to survive the encounter and putting certain tanks who had self-healing abilities (like paladins and death knights) in the spotlight. The DPS race was still part of the encounter, with spores providing the same buff to critical strike chance as it did in the old encounter.
One of the complaints about the new Loatheb fight was that it did not retain the same feel and urgency as the prior iteration of the fight. I wholeheartedly disagree. The original Loatheb was a punishing fight that required precise consumable usage rather than precise player ability usage. The main theme of the redone Naxxramas was having the players bring their skills and roles, and the encounter would provide the rest. Loatheb required many items, potions, and extra items to be completed, for the most part, and a lot of players were not going to be bothered. Accessible raiding is not just a term used to mean "let casuals raid." In fact, accessible raiding is really about getting new, different, and increased number of types of players to raid. There are tons of good players out there who can do the new Loatheb who would have never completed the original, but for their commitment to the raid game and the onus of raiding back in the day.