Negative numbers in Base scores


I had this idea for a podcast article, but wanted to bounce it around here first.

Gang, if we allow negative numbers, I think it makes the magic system easier to use. I want to run this past some other sets of eyes because when I did City and Gild, the playtesters vetoed percentages, then 5%/10%/20% as too difficult, so maybe I like numbers more than other people. On the off chance: here's what I'm thinking. By using negative numbers we can take out the change of scope in magnitudes. You know how it now goes Base 1,2,3,4,5,10,15... and the adjustments are +1 Magnitude for each change of Range above Personal, Target above Self, Duration above Momentary, and volume?

What happens if we instead make it Base -15, -10, -5, 0, 5, 10, 15...and the adjustments are +5 for Each range above Range above Personal, Target above Self, Duration above Momentary, and volume above (in this case) an Animal of Size 0 or less?

So far as I can see, for spells with a Base Effect level of 5 or more, there is literally no change.
For spells with a base effect of less than 5, the math is easier because it is in clear steps.
If the ultimate level is less than 1, it would have been so close to 1 in the old system as makes no odds. So for magic item creation you'd deem it a 5.
Flattening this way doesn't seem to affect the Arts progression.

It may make it easier to rework magnitudes, which might draw the Ability and Art frameworks back together in some variants.
Flattening this way, if it works, may open the way to changing what counts as 0, For example at the moment the system is designed around Forumlae with sponts as Casting total/2 or 5. You might instead design it around sponts, with no fatigue halved and formulic doubled.

If I understand you correctly, instead of casting that level 2 InVi to know if there is an aura by swallowing the air around me, I could cast a level .. -10 ?

I really don't get the advantage in comparison to the old system. The 1-5 range of magnitude for spells is IMO and from what I experienced with new players the hardest thing because it almost never is used.


  • Most people with negative feelings about numbers have especially negative feelings about negative numbers, which does not multiply to become a positive.

  • This rule does have an interesting, perhaps positive effect: Spells whose current level is less than 5 become much easier to cast spontaneously, regardless of Art scores, since magi rarely have difficulty coming up with Casting Total of 0 or less, even after division by 5.



So... For casting spontaneous, no fatigue casting, your breakpoints become 0x4, 25, 50, instead of 5, 10, 15, 20, 25, 50.
The all-star zeroes apprentice casts roughly as powerful as his all-8s mentor, and the specialist-in-Terram casting Imaginem.

If the idea is to make spontaneous magic easier, I like the idea of going negative on T: Individual. ie - if you want to affect something smaller than the default size, it becomes easier. so - 1/10 the volume is a -1, 1/100 is a -2, and so on. It makes for easier spont magic for small things, but keeps the difficulty for larger things.

I also like the idea of using T:Self for creating things that the magi is holding. So creating a 1-lb rock in your pocket would be T: Self - but creating a 200 lb rock would have to be T:Touch, as that's outside one's 'self'. (Although I suppose you could use the "half the weight of the target or less" for that particular effect. Or "light encumbrance", if you prefer something more restrictive.)

How does this truly clean things up with regard to magnitudes? What if the base is 8?

I did an adaptation of the rule for my "mathematically impaired" friends, by dividing every thing by five and to count in magnitude instead of level. It lead to the spell guideline with negative value. There was no problem at all. For spontaneous casting, the minimum was 1 magnitude (so 5 level) and I believe this limit should stay - no matter how low it is level according to the guideline, you need to call on a certain quantity of magic to manifest anything.

It would be similar to Rituals which are at least level 20. Any spell would be at least level 5. Which means that you need to achieve a casting total of 10 with fatigue and 25 without when you want to spont' cast.

I am not sure I would be so much in favor of not dividing, it would be leading to larger numbers, which tend to scare those not mathematically inclined. It also minimise the impact of characteristics (which I don't really mind), and magical aura (which I find more annoying).

Talking about magical aura, currently depending on the local aura, it can easily make a difference of one magnitude for a mage - more with negative aura. If Arts are doubled for spell casting, the impact of aura is halved, becoming less significant.
And I don't like the solution of having to multiply the aura effect by two, because at the end, the only effect would be to multiply everything by 2 except for spont casting. Can you explain again the benefits it will bring ?

To sum up:
Changing the Guideline so increments go by 5 all along the scale would make it easy for computation, while maitaining a minimum of 5 to achieve anything. Nothing else need to be changed.
Doubling the Arts when casting requires to adapt Aura, review the enchantment rules (for consistency sake I cannot see to double Arts for casting but not for enchanting - it will leads to confusion), adjust the effect of virtus used to boost casting, adjust virtues/flaws impacting casting total... that's a lot to change and I don't see the benefit.

I think this would be the most significant change in my games (not the only one, but...). See, in my games, non-fatiguing spontaneous magic is a big deal: spontaneous means unlimited choice without needing to learn any formulae, and non-fatiguing means no chance of botching (so, a few hundred castings over half an hour are perfectly ok). Surprisingly many effects cast by young magi, or by elder magi outside their specialties, are thus level 3 or 4, and with the standard rule this requires a Tech+Form+Int+Aura of 15 or 20; easy enough, but not guaranteed, and requiring often some ingenuity to pull off (right arts, talisman bonuses etc.). With the new rule, any apprentice, however untrained, unless of negative intelligence or casting in really hostile conditions, can automatically get that level 4 non-spontaneous effect. A good thing? Perhaps, but definitely not an insignificant change.