|Attack vs. Reflex? No! Make a Dexerity Saving Throw!|
In 4e, an attack could target one's AC. But it could also target one of three non-AC defenses: fortitude, reflex, or will. The names of those three defenses stems from earlier editions, of course. But the innovation in 4e was that they all worked like AC: the attacker rolls a d20, adds appropriate bonuses, and then compares that with the target's AC, Reflex, Fortitude, or Will defense. The one you targeted depended on the power.
In DnD Next, this is changing. Attacks against AC work the same as they did in 4e (and earlier editions), and this includes (as I understand it) certain spells in which one makes an attack roll against AC. But there are no longer such things as reflex, fortitude, or will defenses. Instead, when one casts as a spell at a target, the target often will have the opportunity to make a saving throw so that they can resist or avoid the spell. This is basically the same mechanic as 3e, except that these saving throws no longer are limited to the traditional reflex, fort, and will saves. Instead, as far as I can tell, a given spell could conceivably target any one of a target's six attributes! Spells like fireball that traditionally have reflex saves use a dexterity saving throw. Charm spells use a wisdom saving throw. But there are apparently spells that can require an intelligence saving throw, or a charisma saving throw.
I really liked the 4e mechanic because of its consistency: pick a power, roll a d20, add bonuses, compare to a defense. It made playing DnD with kids easier, too, because there wasn't much math for them to do outside of their turn. I still like that version better.
That said, I see that they're doing with this new system. A major design emphasis in DnD Next, discussed a few months ago on the various Wizards blogs, was to enhance the importance of abilities within the game. This is a manifestation of that. Rather than having a zillion skills that each character must track, and rather than having three additional named defenses to keep in mind, players instead (mostly) just track their ability modifiers and use them to make saving throws and checks. It makes for a simpler character sheet, because now there are three fewer defense numbers, not to mention a far smaller list of skills (you only track those in which you have specific training). Furthermore,there is an elegance in the consistency of how skills and saving throws work that I do recognize. And I LOVE the Next skill system because of its combination of flexibility and simplicity, so that alone may justify the non-AC defense changes.
There are some other benefits to the saving throw mechanic. For one thing, by essentially putting the attack roll in the hands of the target, players will get to roll dice more often when it's not their turn. This should improve engagement at the table, and it provides players with a sense of control when being targeted by a spell...even if it's imagined control.
It also makes character creation a bit more interesting. Min-maxing suddenly becomes a bit more dangerous, because going with the minimum in, say, Charisma suddenly might have combat implications. In 4e, as long as you had a talky-type in your party to handle roleplaying situations, a character could get away with going with the minimum in charisma, dexterity, or intelligence because there was little cost to doing so. Now, doing so instantly makes you vulnerable to an entire set of spells. Some saving throws will probably be more common (probably Dex, Con, and Wis if I was to guess). But the devious dungeon master can choose monsters with appropriate spells to target their min-maxed player's weaker defenses. This is also going to put a huge premium on any items or powers that can boost all saving throws, as well as (because of their pervasive effects) any items that boost a character's ability scores.
So while I do still like the 4e system, I'm going to sign off on the saving throw mechanic in DnDNext...at least until I get a chance to test it in game!