As many people have not been exposed to the inner workings of Dungeons & Dragons 4th Edition, let me first start off with a quick and dirty run-down of the general principles of 4E.
Some of the fundamental problems with 3E and its predecessors were as follows:
1. Class Balance: Due to being largely free-form with regards to multi-classing, 3E players were capable of creating incredibly unbalanced character builds. Prestige Classes, even officially sanctioned ones, only exacerbated this problem. While this system gave a lot of leeway in creating 'flavor' in characters, it could also be horrendously abused by power-gamers. I myself am guilty of this on several occasions.
2. Scaling: Melee characters started out strong but became progressively weaker as levels became higher. Wizards were soft and squishy, but became godly in power as they neared the upper tiers of magic.
3. Strength and Utility: Melee characters were often bored to tears after the initial interest was over, with countless rounds of "I swing my sword at the monster again." Wizards often spent 15 minutes at a time poring over their list of possible spells, of which they could only use one at a time. There was no comfortable middle ground between simplicity and utility.
4. Experience and Rewards: Dungeon Masters never quite knew exactly how much loot the party was suppose to have. In polls done by Wizards of the Coast, it was determined that the vast majority of DMs tended to leave parties with FAR less loot than they were suppose to have. Without rigid guidelines for rewards, DMs were forced to ad hoc them, leading to inbalance.
4th Edition has made huge strides to try to solve these major problems. While this is bound to alienate many players who have played the previous edition(s) for many years, it has many strong points:
1. Classes are balanced. There is no multi-classing. There are a limited number of base classes, who remain functionally identical (except as outlined below) until level 10, and all classes are mapped out to the hard cap of 30 levels.
At level 11 your character chooses a Paragon Path. This is like a very watered down version of a prestige class, offering specialized abilities that make you unique, without sacrificing balance.
At level 21, you choose an Epic Destiny. Is your character seeking to become a Demigod? Or is he just trying to save the world? Like the Paragon Path, your Epic Destiny gives you additional power appropriate to your level, and an additional sense of flavor without making you overpowered.
2. All abilities scale, or are replaced as they become obsolete. All characters are limited to one Standard Action per round, and all characters can only make a single melee attack per round, regardless of their level. In fact...
3. All classes have special attacks, and are limited to the same number of said attacks depending on their level. These abilities are categorized into At-Will, Encounter, and Daily, and they are exactly what it says on the label. Wizards no longer need a hundred spells just to remain useful across multiple encounters, and melee have a solid selection of useful attacks depending on their weapon of choice and the current tactical situation. Melee might be limited to one attack per round, but the sheer amount of things they can DO with that single attack makes it not so bad.
4. Every level from 1 to 30 is laid out with a suggested loot table and experience point budget. The new Monster Manual gives exact experience budget values for all monsters, making a DM's job of setting up an adventure a snap. Simple fill the loot table with the specified number of magic items, gold, and jewels, and spread them around in your dungeon in a logical way. "Purchase" monsters with your experience budget and place them as you like, and you have a perfectly balanced night of adventuring. There is no more fretting over whether the dragon's hoard is too little or too much for the players.
In fact, when it comes down to it, 4th Edition is like like a MMORPG. The developers specifically showed the inspirations they received from World of Warcraft in their development cycle on their dev blogs, and the influence is clear. It just -feels- right to someone who has played both WoW and D&D. Combat is smooth and exciting. Encounters are well-designed and built. Rewards are appropriate and, well, rewarding.
That said, I will be proceeding with the material herein with the assumption that anyone who reads or participates in it has read the D&D 4E source books, or at least has an in-depth understanding of how 4E works. There is simply too much content and material for me to try to explain in order to make all of this make sense, and while I'd love to paste up the PHB, DMG, and MM word for word, I'm allergic to lawyers and lawsuits.



