The goal of power leveling in Diablo 3 is the same as power leveling in any other RPG. The idea is to gain as many levels as you can as fast as you can, and trust me in Diablo 3 it is entirely possible to get to level 60 in just a few hours, and it’s easier than you would think!
First off, in order to power level in Diablo 3 you will want to look into getting together a leveling set. While this isn’t totally necessary, a leveling set will help you level much faster than you would be able to ordinarily. It does, however, usually take a decent amount of gold to buy leveling set items, though, so this method will probably work best if you are leveling a second or third character as opposed to a first character. The items from the Cain set (Cain’s Laurel, Cain’s Raiment, etc.) are especially useful because this is an actual set geared towards leveling characters, but any gear with bonuses to exp gains will work whether it is actually a set item or not. You will also want to make sure that you get a helm with a socket so that you can use a Ruby to push your experience bonuses even farther.
After you have your gear together, Diablo 3 power leveling is all about getting as much experience as you can as fast as you can. Whether you decided to create a leveling set or not, one thing you absolutely need is a decent weapon. Focus on getting one with high damage values, as well as some added survivability. What I mean by ‘survivability’ is features that will help your character survive longer, such as Vitality, Life on Hit, Resistances, and Life Stealing. The high damage count will help you move through packs of enemies faster so you can keep your experience rate up, and the survival stats will help insure that you don’t die in the process.
Now, proceed through the game as normal. Try to keep trips to town, vendors, and other unnecessary activities to a minimum. This includes using the Auction House, as well as selling or identifying items. Just dump your inventory into your Stash whenever you find yourself in town as part of the questing process. You would be amazed how much time this can save. You can deal with all of those items before you get ready to log off for the day. As you proceed through the game, keep a lookout for the following areas & quests, as they tend to give the best XP/hr rates from what I have noticed:
The Imprisoned Angel (Act I)
The Siege of Bastion’s Keep (Act III)
Siegebreaker (Act III)
Prime Evil (Act IV)
Northern Highlands – Watchtower (Act I)
The Halls of Agony (Act I)
The Cursed Hold (Act I)
The Killing Fields (Act III)
Rakkis Crossing (Act III)
Once you encounter them in your game, you may want to go back to the main menu and re-select them so you can go through them a second or third time depending on how you feel about it. I always do. The Areas can be cleared at any time as long as they are unlocked, but the quests can only be completed once per game instance.