Custom item idea

[Kafana]

I have an idea for a set of custom items, and I'm wondering how to calculate their price. Basically, I want to introduce trinkets in my game that give various minor bonuses X rounds per day. My idea is to have these "runes" that are mutually exclusive (you can only have one bound to your person and you can change your primary rune only at certain altars, once per day.

The runes are ranked and will mimic standard spells which can be activated as a free action and the X round use per day can be spread however you want. Invisibility rune rank I will give you invisibility as a free (or maybe swift?) action X round per day, while rank II will give the same effect a number of X + Y rounds per day.

How could I calculate the prices for this and would it break my game if the spells are only lower level buffs and the number of round is very small (like, below 15 for the highest ranks)?

[eggynack]

It's not exactly what you want, but you might be interested in the weapon and armor augment crystals from the MIC. They have the part where you can only use one at a time, and they have the part where there are three power levels for most of them. It's mostly perfect, though the effects may vary from your intent. At the very least, it's a thing worth looking into. If you just want spells that are usable in a limited quantity each day, it seems like you can partially pull that off with the DMG guidelines.

[Kafana]

The crystals aren't really what I'm looking for, and in my opinion are a bit OP, as they can eliminate some interesting challenges at lower levels as far as I've seen (underwater combat for example can be just like any other fight with a bit of gold).

How would I go about calculating the price of something that can be used X number of rounds per day? Note, it's not a question of Z uses per day, but rounds, in any linear combination, similar to the boots of speed haste effect, as well as a few others I've seen?

Does anybody have a mock up formula of how to calculate the prices of these "runes"?

[Theobod]

Dont Augment crystals have to be put into a weapon/armor of a certain quality?
Least - Masterwork
Standard - +1
Greater - +3
is there a least crystal that grants water breathing or freedom of movement? if so, wow cool, if not.... how?

[Feilith]

What if you did something like wands?

Wands are spell level x caster lv x 750.

So your runes could cost something like
Buff spell level x rank lv x some constant gold cost maybe 500gp for easy math

3 ranks each giving 5 more rounds than the rank before so
1 - 5
2 - 10
3 -15

So invisibility a 2nd lv spell in a rank 1 rune would cost 1000 gp to have it inscribed to you

[Theobod]

How would I go about calculating the price of something that can be used X number of rounds per day? Note, it's not a question of Z uses per day, but rounds, in any linear combination, similar to the boots of speed haste effect, as well as a few others I've seen?

Does anybody have a mock up formula of how to calculate the prices of these "runes"?


From the DMG.
Spell level x caster level x 1800 for 5/day (1/5th for 1/day, twice for 10/day etc) Comand word activation (standard), doubled if the object isnt bound to an equipment slot (like these stones may be, unless they require being held, then use forge rod (or a refluffed Forge Rod feat but its unneccesary) in which case no doubling).
if you wanted swift x/day rather than standard then factor the spell level and caster level as though Quicken spell was applied.


EDIT: oh and expensive material components must be payed 100 times to make one of the above, so a 1/day revivify stone costs a bit over 100k :)
EDIT EDIT: Some sample 'Spellstones', assuming you need to hold them to use em
1/day Mage armor stone. 360GP
4/day schorching ray stone (lowest CL) 8640GP
3/day Fly stone 16200GP