I am glad to say I have been writing like crazy, and have almost made it through my first week of stories. Six stories in six days. And two science fiction in the lot.
The other day, during the running, as I was harrying my party into insanity with five rust monsters (mine also have a mouth that does 1-10 damage), I attacked two party members with two d20s, rolled simultaneously. They both came up natural 20s. Much gnashing of teeth among the party, as that means both front people in the corridor were to suffer double-damage. I picked up the dice again to see if I would roll another 20 and get triple damage, and preceeded to throw two natural 19s. Just awesome.
As ever, the players made the standard joke about numerology, which I've pointed out in the past is NOT bogus in my world, but is an actual science ... which means that odd or unusual results, such as the two doubles I rolled, mean something. What it means is subject for interpretation.
Since no one in my party understands numerology, I don't have to produce an explanation. But if they had chosen to understand it, I would have to come up with something.
I know this sounds strange - is numerology a spell? An ability? How do you get it?
It's a house rule. To begin with, you have to be a mage or an illusionist. As a mage, its assumed you've read a lot of books, and you have knowledge of things that have interested you, or which happened to interest your teacher. I let the player pick and choose what, specifically, they know about ... and if they pick 'numerology,' they know something about that subject.
As they go up levels, they get new interests, so a player can up their proto-knowledge of numerology by gaining an 'insight' and thus now 'understand' (it's a levelling thing, we all know how that works). So that's how you start to make things difficult for me, the DM.
The gentle reader might recollect I wrote something about wild magic a year ago. This is magic that operates outside of the principles of spellcasting, and in effect can't be 'controlled' by the user. Wild magic ignores all limitations of time, space or energy, and can behave erratically or poignantly. It can't be predicted, but it can be perceived ... and in the perceiving, it is in fact set into motion.
For example. A numerologist sees the pair of 20s turn up, and sees the pair of 19s turn up, and either produces for themselves an explanation (that sounds good to me, the DM), or I produce an explanation. In either case, a 'good' interpretation is one I'm prepared to play out in the game ... that is, it has features I can see working into the campaign as a narrative ... or even the better term, as 'exposition.'
Let's suppose the numerologist in the party jumps on the idea of a bigger pair and a smaller pair, and declares that "Two pairs of beings shall enter our lives, and they shall be the same, but different." This sounds good to me, and I am at once rationalizing how a pair of greater cyclops and a pair of lesser cyclops managed to get themselves into a situation in northern Germany, or wherever the hell the party is.
In effect, the double die-roll 'conjures' the cyclops foursome, quod erat demonstrandum, by wild magic. Either the player or I throw out a few words of explanation, and time and space refold so that in fact these two cyclops have been pursuing the party to get back the little tin cup the party picked off a gnome peddlar's cart twelve days ago. The cyclops have been looking for the gnome for a month or more, because the cup has properties that make it appear non-magical in this plane, but practically an oceangoing vessel on Tartarus. And it used to belong to their mother.
That this all took place partly in the past is irrelevant. Wild magic pays no attention to time. It reorders the universe the moment it makes itself evident - by dice rolls (numerology) or by pulling a tarot card, or casting rods, or reading tea leaves, or working out someone's astrological chart. As soon as the event is noticed, the interpretation of the event recreates my world.
Now, you could argue that your characters don't know that dice are being thrown for their lives, and obviously can't see 20s or 19s. However, from their perspective, the profound double strike by the rust monsters, and the duplicate way in which the strikes happen in 'character vision,' can only be interpreted by people down on the ground as something truly profound and unique. "Two!" cries the numerologist. "Two creatures, attacking the same way, having the same effect! Cause and effect! We shall encounter ... two sets of two, and they shall be angry!"
It's really all very simple.