Widow, there is a time the
wizard can intercede, interrupting a rival wizard's casting, but the contingency all by itself cannot intercede unless the wizard uses an immediate action to activate his contingency.
And like I've already established, the contingency is aware, but it’s only aware of the condition of the wizard that the contingency is cast upon. The spell is completely unaware of all stimuli that exist beyond the wizard's body. All published sources back up this idea.
Thanee, contingent energy resistance "functions similarly to contingency," but the is still its own spell with its own set of parameters. The language says, "if you are dealt damage... the spell automatically grants you resistance 10." If the description said, "if you take damage, the spell then grants resistance," then that would be different. In the case of contingent energy resistance, the contingency acts before damage is suffered, but it still doesn't react before the wizard begins casting or the dragon inhales for a breath attack. This doesn't change my interpretation.
Herzog, you are the man. Nice job with
Complete Arcane. There are five paragraphs detailing contingent spells on page 139. This is exactly what I'm looking for. Let me quote the text further:
Triggers for contingent spells are usually events that happen to the bearer of the spell, and can include death, contracting disease, exposure to a breath weapon or to energy damage, falling, exposure to a breath weapon or to a dangerous environment (trapped by fire, plunged underwater, and so forth), succumbing to sleep or fear effects, gaining negative levels, or being rendered helpless, deafened, or blind.
The “usually” in the first sentence is exactly the kind of thing a player would pounce on in an attempt to manipulate the spell beyond reasonable bounds, and it should be clear to that player that the DM will second guess such a generous interpretation of “usually.” “Usually” does not equate to “any other trigger the player can imagine.” That should be obvious to everyone, really. The usual triggers are above, but the wizard can also set up a power word or wiggle of the nose to activate his/her contingency. It’s either that or the trigger examples above, each of which require the wizard to suffer the effect first, gaining the benefits of contingency second.
Clearly, all of the above examples involve the wizard being manipulated. None of these triggers even hints at the possibility of a contingency firing when someone begins casting a spell 20 feet away. Yet another source that backs up my interpretation and squashes the idea that the contingency is aware of things beyond the wizard the contingency is riding.
Two paragraphs down, the following can be found on page 139 of
Complete Arcane:
If the bearer of a contingent spell is the target of a dispel magic, the contingent spell might be permanently dispelled (but not triggered), as if it were an active spell in effect on the target creature.
This assumes the wizard is hit with the dispel, whether from the area effect or the target effect. The above paragraph
does not state, in any language whatsoever (it's not even hinted at), that the contingency interrupts the dispel magic and fires first, so there is absolutely zero reason to assume that it does unless you're a player who really, really, really wants contingency to work that way.
This also confirms that disjunction will destroy a contingency before whatever spell the contingency carries is released.
After 20 years, going from the 1989 PHB right up to the 2004
Complete Arcane, considering all novels and rulebooks that have dealt with contingency (Elminster's evasion, Azalin's contingency, various Greenwood novels where the wizard always dies before his contingencies fire uselessly), never once in any published source has contingency been described as being able to spontaneously fire when someone starts casting a spell some distance away.
Case closed. See you at the table. Set your contingency with a power word.