[hal]

As I've always read it:

Powerstones by themselves, act as an energy reservoir for the use of casting spells.

Powerstones that are created first, then used as a part of an enchantment process for other enchantments, become powerstones with an additional property. This additional property is that for those enchantments that the powerstone was a part of, and ONLY those enchantments that the powerstone was a part of, will the powerstone have twice the energy reserve for those spells than it would have had otherwise.

Example: A mage enchants a 30 point unquirked powerstone. He can use it to power any and all spells he wishes to cast, where the 30 point powerstone can only power 30 points worth of spells.

Example 2: A mage takes that 30 point unquirked powerstone, and embeds it into a heavy oaken staff. The enchanter then enchants the staff with the powerstone such that it has not only the fireball spell enchanted into the staff, but also the sleep spell. He then sells that staff to another mage, who doesn't have the spell fireball, nor the spell sleep. This new mage however, does have the spell FLIGHT.

The mage can cast the flight spell against his 30 point powerstone, but the flight spell uses energy from the powerstone on a 1 for 1 basis. However, the mage needs to cast the fireball spell. He can't cast it on his own, but his staff can, so the spell is cast through his staff - and because the fireball enchantment was enchanted while the powerstone was present in/on the staff proper, it gains the 2:1 energy efficiency. The same holds true when the mage attempts to strike someone AND cast the spell "Sleep". While he doesn't know the spell sleep, the staff can cast it for him. Again, it (the staff) gains the 2:1 capability with the powerstone.

Now we get to have some fun with the STAFF enchantment. Since the powerstone is present while the STAFF spell is being enchanted, the STAFF enchantement gains the benefit of the energy efficiency.

Problem is...

What effects of the STAFF enchantment, require energy to activate? The ability to


Touching a subject with your staff lets you cast spells on that subject
at no distance penalty.


Pointing with a staff reduces the range to a distant subject by the
length of the staff.


A staff can carry Melee spells.

None of the above mentioned capabilities imparted by the enchantment of "STAFF" require energy, and thus, none of those abilities gain a x2 modifier for their capabilities by means of STAFF enchantment. Don't confuse the ability to conduct (ie act as a conduit) spells with the outright casting of spells from the magic item itself.

Note: if you enchant the staff with SLEEP and with FIREBALL, and you remove the gem from the staff, it automatically destroys the enchantments SLEEP and FIREBALL. In a nutshell, the wording has been such, that although you can argue that spells cast through the staff via STAFF enchantments count as gaining the "Doubling of efficiency for energy", none of the spells being cast through the STAFF enchantment really are "enchantments" themselves. In reality, the wording for STAFF enchantment, really only states that the physical "item" (in this case, called a staff), is really a conduit.

Note too, that were you to create a magic item that could only be powered by the powerstone - where you could NOT use your own personal energy to power the item, the energy efficiency increases threefold, not twofold.

So, casting your spell through a staff enchanted with STAFF, is itself, not an enchantment casting a spell, but you using the enchanted staff as a conduit, to cast the spell. Magic items that cast spells on the other hand, are enchantments casting spells through the item itself, not as a conduit of your own abilities, but as a conduit of the enchantment's ability.

Now for the last piece of advice on this discussion...

YOU as the GM, will always be right when running your own game world. If you want it to work such that Casting STAFF on a powerstone embedded in an oak staff makes it act like a X2 energy multiplier, so be it, and enjoy the effects in your game world.

Ok, one final thought and it is off to bed for me...

If you have a person who happens to have the magery advantage, but doesn't know a single spell what so ever, how would you handle the following magic item?

Simple Oak Staff that weighs 6 lbs
Gemstone with 30 points of Powerstone enchanted into it
SLEEP enchantment
FIREBALL Enchantment
ASTRAL VISION Enchantment
BLESS PLANTS Enchantement

Note that each example above, the mage isn't casting a spell. It is the staff itself. When you determine the success for spell casting, you're not casting it as a default from the IQ of the wizard with the enchanted staff, but using the rules in GURPS MAGIC for casting spells by magic item. THAT is how you cast spells THROUGH a staff - or so I've always understood it to mean <shrug>.