Change an item with a daily use into intervals per day

Question

Some magic items say something like, "This effect lasts for 10 rounds. You can activate this ability once per day." Others do this: "This effect lasts for 10 rounds each day, divided up as you so choose."

I would imagine the added flexibility of being able to divide the allotment up would make the item cost more (though you are getting the slight disadvantage of needing multiple standard actions to activate it each time).

Are there any guidelines for converting a "10 rounds, 1/day" item into a "10 rounds/day" item? If not, is there any way to extrapolate based on listed items? If not, are there any other ways of determining a good price (other than DM eyeballing)?

Answer 1

Boots of Speed Are One Example Where It's The Same Price

They didn't divide those up into separate effects in the guidelines for creating magic items. So the only way to determine this is to look at some examples and try to see what they're doing.

Boots of Speed let you get Haste for 10 rounds a day, split up any way you wish, for 12,000g. They got that price as follows:

Haste (10 rounds), spell level 3, caster level 10. That gives us a cost of:

3*10*2000 = 60,000. But that gives you five charges of a CL 10 casting, and the boots only work for 10 rounds (a single casting). Thus, to get one charge, divide by 5. Final price: 12,000g.

That's an exact match. I'm sure you can find cases that don't match perfectly, but this shows that they don't place an extra gold value on splitting the rounds up.

Pricing Should Be Determined Individually For An Item

Why do they do that for some items and not others? Item pricing is an art and the rules flat out say that in the rules:

Not all items adhere to these formulas directly. The reasons for this are several. First and foremost, these few formulas aren’t enough to truly gauge the exact differences between items. The price of a magic item may be modified based on its actual worth. The formulas only provide a starting point. The pricing of scrolls assumes that, whenever possible, a wizard or cleric created it. Potions and wands follow the formulas exactly. Staffs follow the formulas closely, and other items require at least some judgment calls.

When determining the price of an item, you can't just use the formula given and call it a day. The prices in the DMG are hand-edited after using the formula, as the formula is itself a guideline. If you think being able to split the rounds up into multiple uses suits the item, do it. If you think it's too powerful for a given item, then don't do it, or raise the price appropriately.

In the case of Boots of Speed, would you pay 12,000g for a 1/day Haste¹? With the rounds being able to be split up, it can be used over multiple fights and helps the item be more useful. IMO, it'd be rather weak if they didn't let you do that. It could be different for other spells (an item granting free action Righteous Might would be more powerful, for example).

¹You can reduce that to 6,000g for a 1/day Haste that lasts 5 rounds instead of 10. Either way, you use it in a single combat and the item is now useless for the rest of the day. The item as listed in the DMG can be used in multiple fights if you don't burn all 10 rounds in one combat, which helps maintain its usefulness over the course of an adventuring day.

Answer 2

It depends way too much on the effect in question, and as you note, the activation cost. The magic item pricing guidelines don’t even bother to suggest pricing for changing durations, other than for Continuous items. Going from 1/day to 10/day would, according to the guidelines, multiply the cost by 10, but at that point the Continuous item is, according to the guidelines, cheaper.

I would guess that in most cases, it’s better but only marginally so. I’d probably eyeball it, leave most items’ price alone since 1/day effects are often overpriced, and on others give something like a 25% surcharge, or just not allow it to happen. It really depends.

Answer 3

I don't think there is any specific rule addressing this. You could just use the rules for command word activated items. Those aren't OGM as far as I know, so I can't go into detail here.

I think the main problem here is, that the effectiveness of the change would largely depend on the spell/effect bestowed. For example lets assume a swift action or standard action activation: A 10 rounds Freedom of Movement effect would most of the time be a lot better, if you could split the duration, since you could use it to escape for example 5 grapples. A 10 round deathward would still be better sometimes, but often it wouldn't change much, since you'd want to be protected each time on the opponents turn.