Now that my group’s played Aethertide for a couple sessions, I’ve had a chance to see what does and doesn’t work with the magick system. Here’s what I’ve come up with (which I happen to think is pretty neat).
Spheres & Rankings
What you can do with a given sphere is determined by the limits in Mage: the Ascension. The die rating in a Sphere corresponds to a dot rating:
d4 = one dot, Apprentice
d6 = two dots, Initiate
d8 = three dots, Disciple
d10 = four dots, Adept
d12 = five dots, Master
Pushing Beyond Those Limits
Given the conceit of Aethertide — that mages used to have higher-ranked spheres — you can push yourself to do a higher-level effect. If you want to do an effect that’s one rank higher than yours, add a d4 to your roll. You’re more likely to accumulate paradox. If you want to do an effect that’s two ranks higher, pay a Plot Point and add two d4s to your roll. It’s exhausting and troublesome to push yourself that far. You cannot push yourself beyond two ranks.
When you’re doing a magickal action, start by describing the intended effect. You’ll need the right sphere(s) to pull it off, as per above. We also figure out if it’s coincidental or vulgar.
When To Not Roll
Don’t roll if the situation is not complicated. You succeed automatically. This in particular is when the moment is calm and you’re doing a simple rank 1 scan of something. When you do this, the GM will give you information. You can pay a Plot Point to turn that into an Asset for as long as it’s relevant.
- Take one die for your Avatar (a d6 to start). (Edit: I’m removing this for now as an experiment, but not taking the time to update the rest of the post.)
- Take one die for your Sphere. If your effect spans more than one sphere, take the lower die. Magick is harder today, yo.
- You may take one die for a Distinction, either as a d8 for it helping you or a d4 (and claiming a Plot Point) if it hurts you.
- You may take one die for an Option, such as a Focus or Relationship.
- You may take one die for an Asset.
- You take dice from the opponent’s Stress, if any.
- Are you skullfucking reality? Take a d4. Paradox is likely to happen, yo.
- If you want to add in another Sphere or Option die, you may pay a Plot Point to do so.
The “Are you skullfucking reality?” question is more or less “Is this vulgar?” The first time I asked this in play, there was a little heming and hawing, not unlike when we played Mage years ago. So I immediately reframed the question to the above, and the answer was clear. (In prior versions of this rule, you also get a d10 for saying yes. I decided that was a silly idea.)
[Designer's Note: As it is, I think there's one too many dice you can take in the middle section. It makes sense to allow Assets & Stress to always be grabbed, but Distinctions & Options seems like too many. We haven't solved that yet. It could be that I just solve that by default rolling 3d6 instead of 2d6. (I may also change what Focus do again; they originally allowed you to add in a third die for free, which was super potent.) I could also ditch Avatar, maybe.]
Example: Atlas Six is up against a psychotic Reality Deviant dressed as Emperor Palpatine & throwing around lighting. He’s going to use his integrated thermal lance (a focus) to do a Forces effect: melt the guy’s face off up close. He takes a d6 from his Avatar, a d8 for his Forces, a d8 for Primium Laced Exoskeleton (explained by talking about how it stores energy for such purposes), a d4 for his relationship with Abby, the “friendly” reality deviant he’s protecting from Emperor Gothsalot, and a d4 for skullfucking reality by using an piece of Technocratic cyborg gear out in the open. That’s: d6 d8 d8 d4 d4.
If he wanted to do it from a significant distance, he’d probably have to also use Correspondence, which he has at d6. That would mean his Sphere die would be a d6, though he could add in his Forces d8 at the cost of a Plot Point.
Roll the dice you’ve collected. Set aside any 1s; that’s Paradox. Take the two highest of those that remain; that’s your total.
Option: if you want to add more dice to your total, you may spend a Plot Point to add another non-Paradox die you rolled to your total. You may keep doing this until you’re out of non-Paradox dice. In addition, the die type with the highest number is your effect rating.
Another option: if you want to reroll your dice and you used a role, you may spend a Plot Point to reroll any or all non-Paradox dice.
Compare your total to the GM’s. Depending on the action, you may need to meet or beat. (Typically meet in a Simple Action, beat in a Fight Action).
Example: Atlas rolls his d6 d8 d8 d4 and gets 6 & 3 on his d8s, the 5 on his d6, the 1 on both his d4s. That’s one Paradox die, and a total of 11 (6 + 5). His effect rating is d8 (the highest die is a 6, on a d8). That beats the GM’s 9, so he wins.
He could raise that total to 14 by spending a Plot Point to add the three in. He could not however add the 1s in, because they’re Paradox dice. He could also reroll any of the non-Paradox dice. He decides not to, this time.
What Happens When you Win
You get your effect. In addition, you can create an Asset rated at whatever your highest rolled die is rated at, or you can do Stress equal to your highest rolled die.
Example: Atlas won the action. He applies stress to the Emperor, d8 Injured. The Emperor flees. Altas could give chase (or use a Correspondence effect) if he wanted.
What Happens When you Roll Paradox
This is where doing coincidental or vulgar magick comes in. If your magic is coincidental, it takes two Paradox dice to trigger Paradox. If vulgar, just one. If you trigger Paradox, you have a choice: swallow the Paradox, doing Stress to you equal to your effect rating; or unleash the Paradox, where the GM twists the effect, possibly causing a Complication or unwanted Stress to another nearby character.
When this happens, the GM “buys the Paradox” from you, giving you a plot point.
Example: Atlas rolled two paradox dice. Since he was doing vulgar magick, it only takes one die, so the second one doesn’t matter (except that it can’t be added or rerolled). He decides to unleash the Paradox rather than swallow it, because he’s already taken d8 Injured stress, and he doesn’t want to pile more on. The GM twists the effect by saying that it causes backlash, igniting a nearby gas main and getting Abby hurt in the process. She takes d8 Injured Stress. Oops!
What Happens When you Lose
If you lose, and you are pressed for time (like in our example), you don’t pull the magick off in time. If you aren’t, then the magick is pulled off, but a d6 Complication comes with it. When you lose, don’t worry about Paradox. (That last bit might get changed later).
 In Mage: the Ascension games, there’s always a gas main nearby. That’s just fact.
 Which is to say, how Dresden Files RPG handles magic fucking up. Handy, that. :)