iwatt said:
I have no problem mechanic-wise (i.e. allows a soft character to survive, with an abilty long associated to his class...quick reflexes). My question was one of description. When the mage player asks mne how the hell he avoided an instantenous effect, I want to be able to explain it.
For the main topic, the answer is that saving throws are instinctual, not conscious. In general, you get a full fledged saving throw whether you are stunned, asleep, unconscious, or bleeding to death at -9 HPs. (We make exceptions for healing and teleporting unconscious friends for reasons of playability.)
As for your particular question iwatt, instantaneous is a mechanical description for game purposes, not a scientific description. Most actions take 'zero time' mechanicswise -- we resolve them instantly. But we know it takes more than 0.000 seconds to load a crossbow or drink a potion. We resolve certain effects as instantaneous for practical reasons -- in order to create an unambiguous order of effects to resolve one at a time; there are other equally or more logical or realistic alternatives that would be too arduous to use in play.
I picture Fireballs as swirling jets of fire that
roughly fill the whole space in a
short period of time, not as a homogenous sphere of fire that blinks on then off. Someone who makes their saving throw has presumably ducked, dodged, or twisted into a non-fire volume within the Fireball area of effect. Those with Evasion are particularly skilled at this maneuver. And, yes, heroes can even do this in their sleep.