Chance based magic items?

[amateurliar]

Trying to write up a magic item for the game I DM. It started life as a piece of Reflecting armor (spell turning once per day), but I'm trying to alter it a bit to fit our game a little better. I've never much cared for "once per day" items because in my experience they never get used. You end up saving it for a rainy day that never comes and eventually forget that you have it. Having rolled up all the items that are sitting unused in my players' back pockets, I know they're as bad as I am in that regard.

So instead I'm leaning towards a chance based trigger with this suit of armor. For now, let's say it's a 10% chance of turning any spell cast against the wearer. Problem is I have no idea how to price this thing, both in terms of monetary value and possible impact on the game. I haven't been able to find a lot of useful guidance on chance based effects, and price wise the only comparable items I know of are the "Reflecting" shield quality, which is apparently worth an astounding +5 bonus for an effect you get once a day, and the Ring of Spell Turning, which costs the GDP of a small country.

Any advice on this front would be much appreciated.

[Dastis]

I would calculate the value of a continuous version then divide by 10 to represent it working 10% of the time

[gatherer818]

Maybe reduce it slightly further from Dastis's suggestion if it can't be suppressed by the wearer, so it has a chance to reflect beneficial magic.

Definitely price it as a specific armor or a gold cost bonus, not a + bonus, if it only works 10% of the time and has a drawback besides.

[Sotuanduso Storm]

amateurliar wrote:

...the only comparable items I know of are the "Reflecting" shield quality, which is apparently worth an astounding +5 bonus for an effect you get once a day, and the Ring of Spell Turning, which costs the GDP of a small country.

Well, if you consider the price in the guidelines for pricing magic items...

Calculations:

The spell is 7th level for a wizard. This means that being "use activated or continuous" with a duration of 10 min/CL, it would have a price of the spell level * the caster level * 1,500 gp. This comes out to 7 * 13 * 1,500, or 182,000 gp, assuming minimum CL. In the "Reflecting" shield quality, it only triggers once per day. Thus, the price gets divided by 5, leaving 36,400 gp. However, there is a 100 gp material component. Because this item has a daily limit but no overall limit, this would have to be factored in at 50x its value, increasing the price to 41,400 gp. This is between the price of a +6 and a +7 bonus (36,000 and 49,000)

Spell turning once per day is worth 41,400 gp, more than a +6 enhancement bonus, which would be a +1 bonus plus the reflecting property, plus 5,400 gp saved. I would consider that to be a good deal.

As for the Ring of Spell Turning...

Calculations:

Borrowing some of the numbers from above, the price for this would start at 7 * 13 * 1,800 gp, which is 163,800. Being usable 3x/day, it has 0.6x price, or 98,280 gp. Add in the cost of material components, and you get 103,280 gp.

It could have been priced at 103,280 gp, which is the GDP of a slightly-more-than-small country.

My advice is to accept the prices given, and be glad that the writers didn't price them according to the guidelines.

As for pricing the 10% chance, I would probably start with what Dastis said...

Dastis wrote:

I would calculate the value of a continuous version then divide by 10 to represent it working 10% of the time

Calculations:

Base cost for the effect constantly, as in the first calculation box, is 182,000 gp. Drop it 10% as he said for 18,200 gp. Because of the material component and lack of charges per day (instead having a 10% chance), the price would have to be increased by 100x the material component, or 10,000 gp, leading to 28,200 gp.

The effect should cost 28,200 gp. I would be prone to question this and raise the price if you predict that the player wearing it would be targeted by more than 5 spells in a typical day of adventuring.

As for what gatherer818 said...

gatherer818 wrote:

Maybe reduce it slightly further from Dastis's suggestion if it can't be suppressed by the wearer, so it has a chance to reflect beneficial magic.

Definitely price it as a specific armor or a gold cost bonus, not a + bonus, if it only works 10% of the time and has a drawback besides.

...That cost reduction would probably not apply here, as it is considered continuous (despite the 10% chance), and the spell itself already reflects friendly magic. I definitely agree with you on pricing it as a static increase, though. If, however, it is to be priced as an enhancement bonus, I would likely put it at a +5, because that is the closest match in raw gp value.

[Cevah]

amateurliar wrote:

I've never much cared for "once per day" items because in my experience they never get used. You end up saving it for a rainy day that never comes and eventually forget that you have it.

Change the 1/day on command to 1/day first occurrence usable. Now it gets used.

amateurliar wrote:

Any advice on this front would be much appreciated.

Rather than turn 10% of the time, why not Dispel Magic on hostile spells? Cheaper spell, still prevents trouble when it works, and gets d20+CL of item for dispel effect on wearer only.

Weapon or Armor of spell storing is similar and can hold a dispel.

Dispel 1/day = 6,000 gp.
Since the armor must be a min of +1 to add the storing to it, the +1 bonus cost is min 6,000 gp. Leaving it +1 also accouts for the rising cost for rising CL of the item.

/cevah

[Create Mr. Pitt]

The problem with the dispel suggestion is that caster levels of items never increase so it slowly becomes a useless item.

I think even 28k sounds too high for functioning 10 percent of the time, because even if the math works, the exponential loss of the protection 90 percent of the time makes this item not super useful (especially since it works on beneficial spells as well).

I think 15-20k would be reasonable, but this is a stab in the dark. A better idea is a) don't price it at all, allow them to find it; b) come up with some narrative reason it is unsellable (maybe it belongs to a powerful family who would just take it back if they found out it was on the open market). This is not a game-breaking item by any means. I always worry more about impact than value as GM.

[Cevah]

If your player later bumps the enhancement, that also bumps the CL of the armor, thus scaling the spell.

Or you can make it a legacy weapon at +2 bonus that CL=Character level. Or +3 and it becomes greater dispel at 10th or 11th also.

/cevah

[Sotuanduso Storm]

Create Mr. Pitt wrote:

...the exponential loss of the protection 90 percent of the time makes this item not super useful...

I might not be understanding something here, but how is a 90% chance of not functioning an exponential loss of protection?

Also, the usefulness is a direct corellation to the amount of spells the user may face on a given day. And if even one of those spells gets that 10% chance and reflects, it is already about twice as cost effective as what it could have been for a static 1/day. Each additional spell that triggers it is that much value all over again.

And anyways, it is far more useful than what the party already has and never uses. And imagine the surprise when the evil wizard that cast Power Word Kill hits that 10% chance and dies.