Item of Level Loss

[kbob]

Is it possible, per rules, to make an item of continuos level drain? My reason for asking is that if it's possible, would that mean, any undead wearing such an item would gain levels? It would seem to be "yes" to me tho certainly broken.

[Vaern]

Yes, it is possible to create an item that has a continuous level drain effect.
There are items already in the book that apply negative levels to their wielder. In particular, aligned weapons being used by someone of the opposite alignment, but I don't think this is quite what you're looking for.
It would also be possible using the guidelines for creating custom magic items to make an item that continuously drains levels, ie. applying the effect of Enervation to whoever is holding it each round. You can expect anyone using such an item to be dead within a minute or two, tops.

No, there is nothing to indicate that an undead creature would gain levels or hit dice from such an item.
As far as I am aware, though, there are no spells which apply negative levels that also have the opposite effect on undead. Instead, Enervation and Energy Drain only grant temporary hit points rather than temporary hit dice.
As far as I can tell there are no creatures that gain temporary hit dice by bestowing negative levels on a target with an energy drain ability. Spectres, nightcrawlers, and vampires all have energy drain abilities that bestow negative levels, and each of them gains temporary hit points in exchange for consuming the target's life force. Some other creatures gain other miscellaneous bonuses by draining energy, but nothing that I'm seeing gains hit dice.

[Arael666]

As far as I can tell there are no creatures that gain temporary hit dice by bestowing negative levels on a target with an energy drain ability. Spectres, nightcrawlers, and vampires all have energy drain abilities that bestow negative levels, and each of them gains temporary hit points in exchange for consuming the target's life force. Some other creatures gain other miscellaneous bonuses by draining energy, but nothing that I'm seeing gains hit dice.

If we're using enervation as base for the item, we need to check the spell first, wich says that "An undead creature struck by the ray gains 1d4×5 temporary hit points for 1 hour. ". By general magic rules these temp PV wouldn't stack, since they come from the same source, but you would get a const refresh to your temp hp. Also, temp hp has some weird interections, I remember someone saying that temp hp always stacks, but I can't confirm nor quote that.

[Vaern]

I did mention that Enervation and Energy Drain grant temporary hit points.
The description of temporary hit points doesn't indicate whether or not they stack, but I did a quick search and found another thread in which someone quoted a more detailed FAQ entry regarding temporary hit points saying that, unless otherwise specified, temp HP from multiple instances of the same source do not stack, but temp HP granted by multiple different sources do stack with each other. If one application of a single effect is more powerful than the one already in place, the more powerful instance replaces the weaker one.
So an undead wearing, say, a ring of continuous Enervation wouldn't stack temp HP through the roof, but it would gain a fresh damage shield soaking 5-20 damage every round.

[Kayblis]

Undead are not affected in reverse by everything that uses negative energy. Undead are immune to most negative energy effects, are healed by inflict spells, and get temporary HP when the effect is not HP damage. There's no case in the D&D material in which a level drain effect gave extra HD to undead.

[lbuttitta]

Yes, this is possible. However, how the effect would actually play out when used by an undead would be... complicated. Normally, when an undead creature would gain a negative level, it instead gains 5 temporary hp. However, the only cases where this interaction is stated to occur is in negative level-granting effects like enervation or energy drain, and that interaction is explicitly called out in those effects. Since it's not called out in other, negative level-granting effects, the assumption would be that that undead only gain temporary hp from effects that explicitly call it out.

As for gaining HD, no such interaction has ever been documented that I know of. You could allow it, but gaining HD seems like a cheesable effect (although exactly how it would be done, I can't think of off the top of my head.)

[kbob]

Thank you! This helps a lot.

[Vaern]

You could allow it, but gaining HD seems like a cheesable effect (although exactly how it would be done, I can't think of off the top of my head.)
I don't think there's guidelines for pricing an item that replicates a class feature, but if it's reasonably possible then I'm inclined to say the simplest way to boost your hit dice count would be to create an item that grants the effects of a bard's Inspire Greatness ability.

[Kayblis]

The thing is, there's no general guideline that applies to undead and negative levels - every effect that causes negative levels states what happens when you whack undead with it. The only general effect that applies to undead specially is negative energy damage heals HP, positive energy heals deal HP damage. In text, it just states "Negative energy (such as an inflict spell) can heal undead creatures". By the rules, if an effect doesn't specify special interactions and the creature's types and properties don't make him immune to the effect, the effect works as normal. Undead are all immune to energy drain by default, so any energy drain effect has no effect on them unless it states specifically "this happens with undead". This is used in CharOP, as being a Necropolitan is a common way of avoiding Level Loss effects from items and such.

There's no ruling anywhere about just switching the effects of any negative energy spell. Wizards was very set about not handing out free HD as effects, as only the Bard's Inspire Greatness ability is able to do that.

[kbob]

This was all very helpful