Mana Cells for Magic Items

[Adelus]

I'm working on statting up some enchanted weapons filling the role of firearms for a setting with higher availability of enchantments, and I'm trying to get an analogue for ammunition, but most of the options don't seem very good for it.

Powerstones are highly expensive and have recharging limitations that make for difficult logistics and maintenance, especially if these weapons are used by members of an organized military. Manastones are cheaper and have less of the recharging limitations, but are still fairly expensive and can be used independent of enchanted items, giving them more flexibility than desired.

Spell Stones don't really make sense as ammo for weapons because the stone by itself encapsulates the entire spell effect, so the only kind of "weapon" you'd need would be an automated stone grinder. The Spell Charges system from Pyramid #3/36: Dungeon Fantasy is very nice, but this doesn't fit the idea of having reloadable ammunition; the weapon itself would just have so many charges before it is rendered useless on the field.

To that end, I'm looking for something like a Power Cell, but for magical devices. Some of the criteria I'm thinking of are:

1. Enchantment-specific. It might help to lower the costs if they can only be used to power enchanted items, rather than also be tapped as Power/manastones. They also do not provide spells themselves, as Spell Stones and Spell Charges do - an compatible enchanted item is needed, which they just provide power to.
2. Degrees of specialization. Standard cells would be universal, and can be used in any enchanted item that accepts them. Others might be specialized for greater efficiency based on College (or even spell/model) and be unusable for other applications. Likewise, there should be differences between Enchanted items that can accept power from any source, and those that can only accept power from Mana Cells (and some from only specialized Mana Cells, which might be a trade or military secret to prevent use by rivals).
3. Re-usability. Mana Cells should be rechargeable by an enchanter for repeated use. Significant or repeated failures during recharging might permanently knock a point or two off its capacity and bar further enchanting for increased capacity - gradual use will eventually "deplete" a cell and render it inert and unusable for further recharging or enchanting. Depleted cells might even become a nuisance for safe disposal, and have magic-suppressing qualities.
4. Dangerous. Mana Cells may have more capacity than you get out of Manastones and Powerstones, but they are also a little less stable. Destruction of a cell might not just disenchant it, but release a burst of mana that can be destructive or disruptive in a random or college-specific fashion. Critical Failures while using a Mana Cell might temporarily leave it inaccessible, use up charge without powering an effect, or worse.

So, to these ends, I'm offering up this spell write-up.

Mana Cell
Enchantment

Infuses mana into an object to create a store of mana aspected for use in enchanted items. Traditionally takes the form of gemstones, magical metals, or similar valuable and small objects built into a frame which can be slotted or attached to other items. Powering an enchanted item requires physical contact, either by touching the cell to the item or inserting it into a receptacle built into the item for this purpose. Each enchanted item can only benefit from one mana cell at a time - multiple cells in contact will render all inert until the extras are removed.

Mana Cells are enchanted in the same fashion Powerstones are, with the first casting producing a charged Mana Cell with a capacity of 1 and each subsequent enchanting adding another point to charge and capacity. Mana Cells, however, can be unstable and have a base Malf. of 17, with Thaumatology or Hazardous Materials (Magic) taking the place of Armoury or an IQ-based weapon skill for the purposes of handling malfunctions. When a possible result of Explosion is given for Malfunction, instead roll on the Critical Spell Failure table and render the Mana Cell destroyed - and possibly the enchanted item it was attached to as well, depending on the severity of the roll.

Mana Cells do not quirk like Powerstones do. A failure on an enchanting roll to increase capacity gives -1 to the cell's Malf. Two failures in a row while recharging will lock a cell's capacity at its last highest value, and every subsequent two failures in a row will reduce this value by one point until the cell is rendered inert.

Mana Cells produced with materials that cost less than ($5*P^2)+($15*P) require twice energy cost for enchanting and get -1 to Malf. Additionally, the object must weigh 0.1 lbs per point of mana contained.

Energy cost for each casting: 5.
Prerequisite: Enchant.

Model-Specific Mana Cells

This variant of Mana Cells will only function with a single model - usually any set of enchanted items produced by a single guild or manufacturer - a sample of which must be present during the enchanting. Though it does not provide any power to other enchanted items, it provides twice the normal charge and capacity when used in this fashion. An item that is further enchanted away from its original model specifications will no longer be compatible, though certain common and minor modifications may be exempt at the GM's discretion.

Device-Specific Mana Cells

These highly specialized Mana Cells will only ever work with a single, specific device they were built for, which must be present during the enchanting. This specialization provides two possible benefits. The first option is to simply provide triple charge and capacity, as it stores energy specifically for a single item's needs with high efficiency. The other option is that the cell can be built to higher tolerances and compatibility with its chosen device, doubling available charge and capacity and setting base Malf. to 19. Additionally, it will now require 2 failures in a row while enchanting to reduce Malf. by one point.

Notes

I'm still very unsure about how balanced this is - especially the material costs. While still very useful, I don't think these should be anywhere near as expensive as Powerstones or Manastones. Additionally I'm not very sure on things for the Item side of the equation - what modifiers to enchanting costs would be included if an item could only use mana cells, or specific kinds of mana cells?

[GodBeastX]

What you probably want is "Power" enchantment. This lowers the cost of using the enchanted item by each level of power. You can get up to 4 points. This can make some spells always on if it reduces the power enough. For example, power 4 item can throw a 4d6 fireball for free.

[Adelus]

Originally Posted by GodBeastX

What you probably want is "Power" enchantment. This lowers the cost of using the enchanted item by each level of power. You can get up to 4 points. This can make some spells always on if it reduces the power enough. For example, power 4 item can throw a 4d6 fireball for free.

While I thank you for the suggestion, forgive me for being presumptuous for a moment: Please read the entire post, because what I was looking to make was something analogous to ammunition, not always-on or self-powering items.

[Jovus]

Rather than 5, I'd peg the energy cost at whatever the energy cost of the spell being powered is. After all, you're effectively creating a dangerous, unreliable way to carry it around pre-cast, and when that runs out you have to recast, if I understand you.

Edited to add: Unless you expect these to be device-interchangeable. Then, yes, 5 is probably a good amount. That's the same as Manastone, which is rechargeable in the same fashion, and effectively the whole deal about not being able to recharge after two failures in a row is your quirk, predetermined.

[Adelus]

Originally Posted by Jovus

Rather than 5, I'd peg the energy cost at whatever the energy cost of the spell being powered is. After all, you're effectively creating a dangerous, unreliable way to carry it around pre-cast, and when that runs out you have to recast, if I understand you.

That's how Spell Stones/Charges work, and I've stated above that I'm avoiding using that system because I want the Mana Cells to be universal in the sense that they work with a wider set of already existing magical items. The idea is that they are an enchantment-specific kind of manastone with some inherent risk of malfunction, and not that each spell is pre-loaded into a specific cell (though you can certainly have both; enchanted weapons powered by cells and Spell Stone grinders or Spell Charge items. Spell Arrow could also be used for launchers).

[Fred Brackin]

1st I have a techncial note on Manastones. They do notn ahve fewer recharging issues than Powerstones. They have no recharging at all. If you use one the Enchantment is gone.

The physical object enchanted can be enchanted again but this always takes at least a 1 hour Q&D ritual same as the first Enchantment and still requiring a qualified Enchanter.

This is why Powerstones rapidly become cheaper than Manastones over time. Powerstones only need to Enchanted once and recharge on their own on a daily basis with only the expense of storing them securely.

This leads to the point where you did really not say anything about Mana Cells are recharged. If this also requires somemone who knows and can cast a Mana Cell Enchantmnt and a 1 hour Q&D Enchantment what you've done is make a Manastone that blows up more often (and might blow up the very expensive enchated item it is plugged into too)..

The bit about slotting the Mana Cell into the device physically and being easily replaceable with another ends up just being fluff with no game mechncial effect. A normal mage with a normal enchantesd item and a regular Manastone just has to be touching both of those things to use them. He could even use a Powerstone or just his own FP.

I think what you need to do is give a biggish price break on the base Item. "Can only use Mana Cells" probably needs to be something like 50% off or more. Enchanted items are very expensive to make but that cost can usually be amortised over _centuries_. You need a good reason why this Mana Cell system is attracative in comparison even with the "blowing up" part.

Then you need to have Mana Cells being recharged by any Mage by touch and an act of will to transfer FP into the cell. That way cells can be recharged by 50cp apprentices as fast as they can regain FP rather than 250cp Enchanters in a one hour ritual.

[GodBeastX]

Originally Posted by Adelus

While I thank you for the suggestion, forgive me for being presumptuous for a moment: Please read the entire post, because what I was looking to make was something analogous to ammunition, not always-on or self-powering items.

Mistook what you said about 'Ammunition'. Didn't know you wanted it depleted after use. You could always alter the mana stone concept in the setting you're in. After all, GURPS magic tends to be for Arthur-style magic use where magic items are far and few between being stuff of legends and isn't a 1 shoe fits all system.

[GodBeastX]

Sorry for posting so soon after my last, but you might want to look in the Thaumatology Material Magic section. It has a blurb about using materials in place of FP.

[Fred Brackin]

Originally Posted by Jovus

Edited to add: Unless you expect these to be device-interchangeable. Then, yes, 5 is probably a good amount. That's the same as Manastone, which is rechargeable in the same fashion, and effectively the whole deal about not being able to recharge after two failures in a row is your quirk, predetermined.

A specific cost for Enchantemnt spells that ends up being less than 10 is not a big deal. You're in the territory of 1 enchanter for 1 hour whatever it is. The Master Enchnter could recharge 10FP on his own in 50 minutes but he could also have _himself_ recharged by one of those Apprentices with the Lend Energy spell.

It ends up being a very minor difference.

If MAna Cells can avoid high matrerial costs and still keep the Enchantment cost at 10 or less you'll never see ones made out of expensive amterials.

[Kuroshima]

Personally, I would not reinvent the wheel. Make them dedicated or exclusive manastones, if you want them to only be able to power a single item.