One key distinction between VATS and RTwP is that VATS provides a tactical view, complete with chance-to-hit percentages, much like the aimed shot display from the original Fallout, presented in the actual game view as a HUD overlay. This isn’t just eye candy; the percentages are exactly reflecting what’s going to happen “behind the scenes.” That’s quite unlike any RTwP system I’m familiar with.
An even more fundamental distinction between VATS and a real-time-with-pause system is what happens when you leave the “pause” mode and the action resume.
In a RTwP system, when the action starts again, you’re simply back to real-time.
In VATS, when the action starts again, you’re not back to real-time. Rather, you’re in a mode where your character acts quickly, while the rest of the world is heavily slowed down. Again, the results of your actions are purely statistics-driven, based on the percentage chances that were presented in the tactical view. And again, that’s different from any RTwP system that I’m aware of.
Obviously VATS is different than taking a turn. But I can tell you, in my own entirely subjective and personal experience, that when I enter VATS, queue up some shots, and fire, it does indeed feel very much like I have chosen to “take a turn” at that moment, in the sense that the world stops and what I choose to do happens more-or-less “immediately” and in a purely stat-based fashion.
Do note that I’m not saying anything new about VATS here; I’m just contrasting the major points of distinction with RTwP. As Brio pointed out earlier, all of this detail and more can be found in the official fan interview; I recommend checking it out.
This and other issues of combat in Fallout 3 are being discussed here. What do you think?