Video game technology has changed a great deal since Fallout 3 released in 2008, even Bethesda has been changed since the game's release. Bethesda crafted a huge open-world RPG since Fallout 3's release (Skyrim) and that game has taught them plenty on what works in a game and what doesn't.
Growth in technology and what Bethesda has learned from Skyrim have shaped Fallout 4, but more than that Bethesda's own aspirations for the game have brought a couple of changes to the way some systems work.
One of these changes is that while Fallout 4 will be an RPG at its core, it will also have more action-oriented features to make the game faster paced. Bethesda's game director Todd Howard detailed that one of Bethesda’s goals was to “make it feel great as an action game.”
In order to do this, the ‘Vault-Tec Assisted Targeting System’ (VATS) has been changed.
Traditionally, entering VATS in Fallout 3 would pause gameplay and allow you to line up shots, displaying the percentage chance of a clean hit clearly displayed. In Fallout 4, VATS will not pause the game, but will continue the action at a very slow pace. According to Howard, this change makes things "a bit more dynamic."
Going into further detail, Howard revealed how VATS would work in-game:
“It’s very, very slow and you’ll see the percentages change because the person is moving behind or coming out of a wall. So queuing up the shot at the right time matters. And while the playback is happening, the criticals are not random, you assign which shot is the critical one and you load up that bar. So it’s a little bit more under your control, not a lot, but just enough to make it feel better.”
TL:DR: VATS will no longer pause the game, but make things slower. You will still see the percentage chance of a clean hit.
