[Magic/Thaum] Pulling FP from ambient mana

[Jerander]

Originally Posted by Rev. Pee Kitty

That's very reasonable. Let me suggest how I would handle this -- it's an approach you can see in GURPS Psionic Powers.

...(snip)...

Draw Mana (?? points/level)
You can pull ambient mana from the air to power your spells. This acts as a reserve of extra FP that can only be used for spells; it recharges itself separately from your own FP, whether you're resting or not. In normal mana, this energy pool is equal to your level of Draw Mana. It regenerates 1 point every 10 minutes; Recovery Energy speeds this up as usual.

In a low-mana area, both the size of the energy pool and the recovery rate are halved (round down). In a high-mana area, both are doubled. And in a very-high mana area, the pool is tripled and recovery is instant!

...(snip)...

Total for Draw Mana 40 = 237. Divide by 40 and you get 5.9 which rounds to 6. So the Draw Mana ability above is worth 6 points/level.

This is beautiful. I love responses like this. Useful and educational. I now have a process I can use to calculate similar abilities. Thank you.

Jerander.

[Jerander]

Originally Posted by Rev. Pee Kitty

That's very reasonable. Let me suggest how I would handle this -- it's an approach you can see in GURPS Psionic Powers.

Total for Draw Mana 40 = 237. Divide by 40 and you get 5.9 which rounds to 6. So the Draw Mana ability above is worth 6 points/level.

Okay, let's see if I can recreate the logic, but slightly different.

Draw Mana (7 points/level)
You can pull ambient mana from the air to power your spells. This acts as a reserve of extra FP that can only be used for spells; it recharges itself separately from your own FP, whether you're resting or not. In normal mana, this energy pool is equal to your level of Draw Mana. It regenerates 1 point every 10 minutes; Recovery Energy speeds this up as usual.

In a low-mana area, both the size of the energy pool and the recovery rate are halved (round down). In a very low mana area, both are quartered (round down). In a high-mana area, both are doubled. And in a very-high mana area, the pool is quadrupled and recovery is instant!

ER 20 (Very Low Mana and up, -0%) [60]
ER +20 (Low Mana and up, -5%) [57]
ER +40 (Normal Mana and up, -10%) [108]
ER +80 (High Mana and up, -35%) [156]
ER +160 (Very High Mana, -65%) [168]

Total = 549

549/80 = 6.9 rounded up to [7/level].

Does this seem right? I'll have to tweek the % of different mana levels, and thus the Accessibility modifier...

Thanks,
Jerander.

[Jerander]

Originally Posted by Jerander

Okay, let's see if I can recreate the logic, but slightly different.

ER 20 (Very Low Mana and up, -0%) [60]
ER +20 (Low Mana and up, -5%) [57]
ER +40 (Normal Mana and up, -10%) [108]
ER +80 (High Mana and up, -35%) [156]
ER +160 (Very High Mana, -65%) [168]

Total = 549

549/80 = 6.9 rounded up to [7/level].

Okay, then, if I wanted different levels of Magery to have access to different levels of the ER, I could recalculate for each Magery level, adjusting for the levels of mana required for the ER to operate.

[Dragondog]

PK states that low mana and up is -0%, while you say it's -5%, and normal mana is listed as -5% and -10% respectively. Though that difference is only worth 9 points so the end result turns out to be the same in this case.

[Jerander]

Originally Posted by Dragondog

PK states that low mana and up is -0%, while you say it's -5%, and normal mana is listed as -5% and -10% respectively. Though that difference is only worth 9 points so the end result turns out to be the same in this case.

He wasn't including Very Low Mana. Also, I'm just giving ballpark figures to play with. I'll adjust the exact Accessibilities when I figure the exact percentages of various mana zones.

[MagiMaster]

Originally Posted by Jerander

Okay, then, if I wanted different levels of Magery to have access to different levels of the ER, I could recalculate for each Magery level, adjusting for the levels of mana required for the ER to operate.

No. Like it mentions in Powers, prerequisites don't alter point costs. Instead, you'd likely just say that you can only buy so many level per level of Magery, unless I misunderstood what you were asking.

[Jerander]

Originally Posted by MagiMaster

No. Like it mentions in Powers, prerequisites don't alter point costs. Instead, you'd likely just say that you can only buy so many level per level of Magery, unless I misunderstood what you were asking.

Let me clarify. I'd like different levels of Magery to have access to "Draw Mana" in at different mana levels. For instance, maybe Magery 4 can draw from Very Low Mana all the way through Very High Mana, but those with Magery 0 can only draw in Very High Mana. Something like

M0: can draw from Very High Mana (VHM) only.
M1: can draw from High Mana (HM) and VHM.
M2: can draw from Normal (NM), HM, and VHM.
M3: can draw from Low Mana (LM), NM, HM, and VHM.
M4+: can draw from Very Low Mana (VLM), LM, NM, HM, and VHM.

Or similar.

I'd also like the different levels of Magery to determine the rates of recharge. So, for instance, M4 would recharge their Draw Mana ER twice as fast as someone with only M3. This will need some playing with to get right. Any suggestions?

Thanks,
Jerander.

[Dragondog]

Originally Posted by Jerander

He wasn't including Very Low Mana. Also, I'm just giving ballpark figures to play with. I'll adjust the exact Accessibilities when I figure the exact percentages of various mana zones.

PK said '"Low Mana or higher" is not really a valid limitation, because magical ER is useless in a no-mana area anyway.' And even if he meant Very Low Mana, normal mana would still only be -5% according to his calculations.

[Jerander]

Originally Posted by Dragondog

PK said '"Low Mana or higher" is not really a valid limitation, because magical ER is useless in a no-mana area anyway.' And even if he meant Very Low Mana, normal mana would still only be -5% according to his calculations.

Right. I'm assuming RPK typed exactly what he meant ("Low Mana or higher") and was using the standard mana levels out of Magic (Low, Normal, High, Very High) in his example calculation. However, for the basis of my sample calculation (to see if I understood the process correctly), I included Very Low Mana as well. To make it similar but not the same.

If Very Low Mana is used (and this "Draw Mana" ability is useful in VLM), then the threshold for being useless in a no-mana area is at Very Low Mana instead of Low Mana. Thus my marking "Very Low Mana or higher" as +0% (for the same reason RPK put "Low Mana or higher" at +0%). Low Mana then becomes less than 100% of the available utility, making "Low Mana or higher" a valid limitation whose value is based on the table under the Accessibility limitation in Powers.

Unless there's something in Thaumatology (or elsewhere) regarding ERs not be usable in Very Low Mana areas that I missed?

[Jerander]

Originally Posted by Rev. Pee Kitty

First, the recovery. Assuming that high-mana areas are at least as rare as low-mana ones in your game, it's a reasonable "special effect" to let the recovery rate scale.

The percentage of NM is immaterial as long as VLM + LM = HM + VHM. But what if the ratio of High Mana areas to Low Mana areas are not equal? For example, what if I have the following distribution:

Very Low Mana (VLM): 11.1% of land area
Low Mana (LM): 22.2% of land area
Normal Mana (NM): 44.5% of land area
High Mana (HM): 22.2% of land area
VHM (VHM): < 0.1% of land area

First, the Accessibility limitation values would be:

"VLM or higher, +0%" (VLM + LM + NM + HM + VHM = 100%)
"LM or higher, -5%" (LM + NM + HM + VHM = 88.9%)
"NM or higher, -15%" (NM + HM + VHM = 66.7%)
"HM or higher, -30%" (HM + VHM = 22.2%)
"VHM only, -50%" (VHM < 0.1%)

Second, the assumption that the recharge rate is a special affect needs to be examined. At a ratio of 3:2 (lower than NM: higher than NM), the ER would recharger slower, on average, than 1-ER/10-mins. But how to weight it?

Third, the averaging of the ER prices (in CPs) would have to examined as well.

I'm going to think about this a little bit. Until then, any input is welcome.

Thanks,
Jerander.