Step-by-step class guides are on the way!  The 1-12 Mulgore Guide is the first guide to get all the individual class steps.  At the top of the guide, simply select which class you are playing and the page will dynamically update all the steps in the guide for that class (both text and images).  The rest of the guides will be slowly updated overtime to include all the class steps, but you can see how it's going to work with the 1-12 Mulgore.  I want to thank crazyK and his Placeholderguild for helping me out with the individual class content.  They are allowing me to get the 1-60 Alliance guide done while also getting all the class steps done at the same time, so everything can be ready for Classic launch (hopefully).
We have some guides to picking out a race and a class for WoW Classic that can help you figure out what to spend those five levels as. And if you’re on the fence about whether or not you’re interested in WoW Classic, we’ve got some thoughts on that as well. For the full announcement of the stress test, head on over to the official forums and take a look. You can help make sure that when WoW Classic goes live, it doesn’t repeat the server shenanigans of the past.
Thanks for bringing this question to our attention. Addons and their availability are a large part of what makes WoW great. Any addon that enhances your User Interface [UI] is totally okay, however, anything that automates your character's play [you can walk away from your computer and your character is still leveling, in combat, etc] is decidedly not okay and falls under exploitation and botting. If you are concerned at all or think the particular addon/guide may fall under that second category, for your safety, I recommend you just stay away from that one as violations of the Botting/Exploitation aspect of the Terms of Use is a bannable offense. If you have any questions about what might be considered automated play, I recommend you refer to the Terms of Use and follow them to the letter. You may find those Terms here: http://us.blizzard.com/en-us/company/legal/wow_tou.html. 

WoW Classic seeks to recreate the "vanilla WoW" experience—that is, WoW as it existed before a series of seven game-altering major expansion packs from 2007's The Burning Crusade to 2018's Battle for Azeroth. To achieve this, Blizzard has rebuilt the game based on archived data from back in 2005 and 2006 (patch 1.12 is the goalpost—the current game is on patch 8.1.5). The company has committed to meticulously presenting the experience exactly as it was back then—warts and all—with only a small number of unavoidable or critical changes.
To fill our pool of beta and stress test participants, we’ll be choosing dedicated players who meet select criteria from both the WoW Classic beta opt-in and the standard Warcraft beta opt-in. Participants will also need to have an active subscription or active game time on their Battle.net Account. While opting-in to the beta is the primary way to make sure you’re in the running to join the test it doesn’t guarantee an invitation to the closed beta test. We may also consider additional factors such as how long a player has been subscribed to the game so that we have the right mix of players to ensure great feedback toward making WoW Classic the very best experience for the community.
Even though the guide was developed with a hunter, the guide can be followed by any class.  Except you have to do your class's quests which aren't a whole lot.  I do have full intention to make my guide friendly with all classes in the future by listing all of their steps as well.  There will be a toggle that allows you to show which class's steps you want to see in the guide.  But this is coming later.

It was the experience of the game that brought pleasure and joy, and that's what a lot of us want again. Not the numbers. When I play Classic I want to go through the deadmines with people I like and overcome a challenge together and see myself become stronger as a result. I don't want to play Classic so I can say "booyah! That number is exactly the same as it was 13 years ago!"
When it comes to levelling the Priest Class from 1-60 fast, XP grinding locations is only half the battle. You will need to make sure your weapon does enough DPS so that you can clear these mobs fast enough, it should also be noted that monster should be around your level to make sure to gain the 100% XP Reward. The Level your character should be before you start that specific location will be indicated to left in a Blue Color for Alliance [Lvl 35-39] and the Orange Color for Horde [Lvl 35-39]. The Mobs you are looking for in that specific area names are Bolded [Mob Name].
But how do you proportionally resize the swing? Even if you did, it wouldn’t give you the same type of joy as when you were a kid, because you have grown up and changed. Even if that wasn’t the case for you, you have to consider that the swing has become a place that is sacred for many other adults. When they visit, they aren’t visiting to try out the new adult-swing. They want to try the old swing. The one that brings back the joyful memories of distant past. They know that the experience isn’t the same, but if they close their eyes ... even for a brief moment ... they just might get that nostalgic thrill that brings them back to a time where things seemed so much simpler. 

But how do you proportionally resize the swing? Even if you did, it wouldn’t give you the same type of joy as when you were a kid, because you have grown up and changed. Even if that wasn’t the case for you, you have to consider that the swing has become a place that is sacred for many other adults. When they visit, they aren’t visiting to try out the new adult-swing. They want to try the old swing. The one that brings back the joyful memories of distant past. They know that the experience isn’t the same, but if they close their eyes ... even for a brief moment ... they just might get that nostalgic thrill that brings them back to a time where things seemed so much simpler.
One of my favorite features is the Smart Injection System, which automatically determines the optimal place for your character to get started with the guides, based on your level and quest history. In other words, it doesn’t matter what level you are currently, you can jump right in and continue seamlessly with the guides. It also means that you don’t have to be a slave to the guides, they work perfectly even if you’re also leveling in instances, battlegrounds, using heirlooms or rested EXP. If your level ever gets ahead of the guide, just use the built-in feature to skip to the right place again. Very cool.
So tonight I took the plunge and thought hey let me buy a Zygor Guides subscription to see how it is. A guide backed by a subscriber base paying for a premium experience this has to be great right? I was wrong. I tested it by loading it up on the Honorboud Rep Guide. Cool it tells me to do World Quests and Island Expeditions. So far so good but hang on... What about the Wanted Quests? Those are by far the biggest boost to reputation. It did not mention them at all. So I thought that's fine it's probably because BFA is quite new. Loaded up a leveling guide on an alt. It was a complete mess. The guide was telling me to accept quests that A) would be horribly inefficient to level with and B) I already done. I also started noticing weird performance issues. Zygor was causing stuttering and FPS dips like crazy. So to close off I requested a refund and the person I spoke to did say I'll be getting one but we will see if that happens. Not getting my hopes up.
Beginning May 15, select WoW players will be invited to participate in a small-scale, focused closed beta test. Players will also get a chance to help put our servers and technology through their paces in a series of stress tests running from May through July—you can opt in now through Account Management and select the WoW Classic beta. Subsequent stress tests will extend the opportunity to even more players. Level caps will also be in place to ensure we’re emphasizing the “stress” in “stress test”
For the duration of the fight, creatures in the immediate area will not be visible to you (but they may still attack you if they wander too close). Keep in mind that other players will still be able to see you and attack you if you are eligible for player vs. player (PVP). Other players will also be able to view your pet battle in real time, including the pets involved as well as their health as the match progresses.
Blizzard also announced a boxed Collector's Edition for World of Warcraft to ring in the game's 15th anniversary. It includes a Onyxia pin, map of Azeroth mouse pad, art prints, special anniversary mounts, and a large black-and-gold statue of Ragnaros the Firelord. It will release on October 8 for $100, and you can pre-purchase from the Blizzard store.
Beginning May 15, select WoW players will be invited to participate in a small-scale, focused closed beta test. Players will also get a chance to help put our servers and technology through their paces in a series of stress tests running from May through July—you can opt in now through Account Management and select the WoW Classic beta. Subsequent stress tests will extend the opportunity to even more players. Level caps will also be in place to ensure we’re emphasizing the “stress” in “stress test”
Only really to expand on Gráinne's comment as regards the 'collecting' and 'roster development' sections - which are, as said 'distinct' although they are intrinsically linked - I would like to point you in the direction of the in-game Achievements > Battle Pets > Collect tab. There are a series of achievements called Raiding With Leashes, pretty much all of which can be completed via the auction house - if you have the gold/inclination - or by completing old raids.
Through out the game, the quest log will be capped to 20 many times.  The guide makes use of maximizing the total amount of quests you can accept at once.  Because of this it is important to follow the guide exactly and only accept quests if the guide tells you to so you won't run into issues not being able to accept a quest.  If you do accept a quest that is not listed in the guide, write it down because you may need to abandon it in order to keep following the guide if your quest log is full.
×