Days of High AdventureDungeons & Dragons Basic Rules First Impressions: The Magic Is BackDays of High Adventure - RSS 2.0
In terms of pure game mechanics, 5e retains most 3.5 elements. Vancian spellcasting is back (yech... I hate keeping track of prepared spells and spell slots, but I realize I'm in the minority). Cleric Domains are back - and, in fact, every class gets some comparable decision to make at early levels, such as a fighter's "fighting style," which includes such options as dueling or archery, or a wizard's ability to specialize in a school of magic (something I sorrowfully missed from 4e). 3.5 multiclassing is back, though the rules that govern it are not in the basic rules. The ability to attack multiple times per turn as you level up returns, but only for fighters. Critical hits have you rolling extra dice again, rather than just maximizing damage as in 4e. Familiar spells return, but the influence of 4e powers can be seen in them - and this influence enhances the spell mechanics.
If there's one thing 4e did well, it's mechanics, and a few of them see a return in some form in 5e. The Cleric's Channel Divinity is back, as are short and long rests, and ritual casting. Second Wind and Action Points return as Fighter abilities, which, when combined with the other options at the Fighter's disposal, make 5e Fighters far more interesting than their 3.5 counterparts. The 4e skill system and grappling rules supercede 3.5's, as does the choice to freely knock out an opponent instead of kill it without having to resort to tedious non-lethal damage rules.
5e does introduce some completely new rules, such as the Advantage and Disadvantage mechanic that have you roll two d20s and choose either the higher or lower result. Feats are handled completely differently; you can only take a feat at a given level if you choose to forgo an ability score increase, so it is possible to never pick up a feat at all. Actions in combat allow you to split up your total movement however you see fit, such as by moving 10 feet, attacking, and then moving another 20 feet, and you can freely interact with one object as part of either your move or attack action. Playing on a grid is introduced as a variant rule, further clarifying the move away from a combat-centric ruleset. A new "shove" attack action lets you either move a creature or knock it prone. And, of course, unnecessary changes have been made to the rules that govern what happens when you fall below 0 HP, as usual.
Bear in mind that these are just the Basic Rules, let alone the Starter Set - there's much more to be seen of 5e. The Player's Handbook is slated to release August 19, the Monster Manual on September 30, and the Dungeon Master's Guide will round out the triad on November 18. But this glimpse into 5e shows promise for the future of this edition, and my only real criticism is that I'm not a fan of the retro-style character sheet design - while easier on the printer, it lacks the bold, black headers of the 3.5 and 4e sheets. But really, if I'm complaining about character sheets, then that's a pretty good sign about the overall direction of 5e, which is a return to the wonderful flavor and sense of discovery that first drew so many of us into the world of D&D.