An intervention is a d666 die roll that indicates either God or Lucifer has taken a personal interest in the oucome. Depending on the result, the roll is more specifically referred to as a divine intervention or an infernal intervention. The exact effects are up to the GM, but can range from the subtle (a slight scent of brimstone turns a demon's head just in time to see the person he's been hunting walk out of a bar) to the overwhelming (lightning falls from Heaven, destroying every demon within 50 feet of the angel who made the roll.)
A divine intervention occurs on a natural roll of 1-1-1. This roll is always good for angels and always bad for demons.For unaligned humans and ethereals, the roll benefits them if they're attempting a good or selfless action, but hurts them if they're trying something selfish or evil.
In canon, an angel who rolls a divine intervention on a dissonance roll automatically has all dissonance removed by God. A demon who does the same not only gets his note of dissonance but also acquires a Discord.
An infernal intervention occurs on a natural roll of 6-6-6. This roll is always good for demons and bad for angels. For unaligned humans and ethereals, the roll benefits them if they're attempting something selfish or evil, but hurts them when attempting a good or selfless action.
In canon, a demon who rolls an infernal intervention on a dissonance roll automatically has all dissonance removed by Lucifer -- though the lucky demon is welcome to wonder why ... An angel who gets an infernal intervention when rolling for dissonance becomes an Outcast; an already-Outcast angel Falls.
Interventions in the Celestial RealmEdit
An infernal intervention has no effect in Heaven -- it's just an ordinary failure. A divine intervention, on the other hand, has full effect in Hell. Rebelling against God ain't easy.
Although it is not included in the core In Nomine rules, some GMs have elected to make 3-3-3 a third intervention, representing either intervention by ethereals, or by Lilith, or just "something weird happening" as a house rule.