The latest and most official rule for 3.5 is from Libris Mortis, which states that a lich cannot create a second phylactery at all, even if the first is destroyed. This contradicts (and supersedes) an earlier (3.0) rule from the Savage Species Lich Template Class. Many thanks to @ColinD for linking those.
Note that if you do not have Libris Mortis or that particular Savage Species web enhancement in play, there is no rule on the subject at all. The lich monster entry states that the purpose of the phylactery is to store the lich’s life force in it, and then goes on to describe how it is made: with no restriction mentioned, it seems possible to create more than one, but the role of the phylactery during the ritual itself and the uniqueness of one’s own lifeforce may imply that the process cannot be repeated.
Note that resurrection and true resurrection return an undead creature to the life they once had. If nothing else, even in the case of Libris Mortis, a lich could do that and then repeat the process of becoming a lich, creating a new phylactery. Any living creature is eligible to become a lich; there is no requirement that they cannot have been a lich previously.
If Libris Mortis is not in play, this can even done to the remains of a destroyed lich, but with Libris Mortis, there is a clause that “If a lich without a phylactery is slain, the lich is forever destroyed.” Whether that only means in the automatic fashion typical for liches, or at all under any circumstances (and whether that is going to trump the rule that undead can be restored to life) are all very ambiguous questions that need to be answered by the DM.
Finally, the dry lich (Sandstorm) may have different rules, since they start with several phylacteries.
This is a kind of musing, rambling answer because there are a few aspects of the rules that I think deserve calling out and considering here. There is no explicit rule on this one way or the other, and I haven’t found any commentary by Paizo, so I am going to have to reason about what the rules do explicitly say to inform an answer. (I am not aware of any examples of this, or commentary on this, from any edition of D&D, but that doesn’t necessarily mean there isn’t one; that would be a lot of material to sift through to rule out the possibility.)
The lich’s phylactery is probably magical, but it’s not actually called out as such.
Basically, nothing ever calls it a magic item. You use Craft Wondrous Item to make it, and that feat generally creates magic items (but the phylactery could be an exception), and its crafting rules require a minimum caster level (but strictly speaking that only says you have to be magical). So there is good reason to assume it is magical, but it’s not spelled out.
It doesn’t necessarily matter if the phylactery is magical.
The lich’s rejuvenation ability is a property of the lich, not the phylactery, though obviously they interact. But ultimately, the only thing that the rejuvenation ability requires of the phylactery is that it be the phylactery—and it’s not clear that a phylactery, even if it is normally magical, ceases to be a phylactery when magic is suppressed.
Dispel magic probably doesn’t come into play.
The lich’s rejuvenation is a supernatural abilities, and those cannot be dispelled. You can argue that you could cast dispel magic on the phylactery, if you have decided it is magical in the first place, and then that the phylactery ceases to be a phylactery while suppressed, but otherwise dispel magic is of no use.
A lich who is destroyed in an antimagic field has rejuvenation suppressed.
This one is pretty clear: suppressing magic around the lich suppresses its magical abilities. Since supernatural abilities are magical, that includes rejuvenation.
The main question is whether or not the lich only gets one chance at rejuvenation. Supernatural abilities suppressed by antimagic field come back as soon as the antimagic field goes away—but at that point, the lich is already destroyed. Can a destroyed undead creature even be said to have any abilities?
Moreover, even if it does, the rejuvenation ability is “triggered” by a particular event, the destruction of the lich. It specifically says “When a lich is destroyed,” not something like “A destroyed lich...” So by suppressing the ability at the moment of that event, does the triggered ability just miss the trigger? Or does it trigger, but get suppressed until it can go?
If a lich is destroyed while its phylactery (but not it itself) is in an antimagic field, then... unclear.
This is basically the same as the question of dispelling the phylactery: can rejuvenation still target it, that is, is it still a phylactery without magic? First aspect of that question is whether or not the phylactery was ever magical to begin with, as discussed, and even if so, whether that was a required aspect of its identity as the lich’s phylactery. Either answer gives rise to more questions.
If the lich’s phylactery wasn’t at the time of its destruction, does that mean it missed its window to rejuvenate? Or does the ability trigger, only to find its target suppressed and so become effectively suppressed itself, allowing it to resume once the antimagic field is over? Or does the triggered ability just fall apart because the phylactery wasn’t available at the time?
On the other hand, if the lich’s phylactery is still a phylactery even though it is suppressed, doesn’t that mean that the lich—in spirit, anyway—moves adjacent to it and thus is now inside the antimagic field? If that were the case, we would have a pretty clear case of the ability being suppressed—after being successfully triggered. That would mean that the lich doesn’t begin rejuvenating until the antimagic field is gone, but then does begin to rejuvenate. And if the lich isn’t said to move yet, and suppressing the magic of the phylactery itself doesn’t prevent rejuvenation, then you would have the lich magically reconstructed while within an antimagic field—decidedly odd, but conceivable, at least under the rules.
These questions basically give rise to a series of options:
- If the phylactery is not magical
Or the phylactery’s magic is not integral to its identity as phylactery
Then
Otherwise (if the phylactery is magical and must stay magical)
Then
- Dispel magic and antimagic field on the phylactery have the same effect as antimagic field on the lich.
Either way antimagic field on the lich suppresses rejuvenation, meaning:
If the trigger is a one-shot deal
Then the lich does not rejuvenate and is dead.
Otherwise the lich rejuvenates once the antimagic field around him (or around the phylactery, or dispel magic on the phylactery, if those are magical and must be so to rejuvenate) goes away.
Since the phylactery is probably magical, and seems to be doing magical things (“phylactery [...] begins to rebuild the undead spellcaster’s body nearby” implies action by the phylactery which implies it is magical), I tend to favor that suppressing magic on it is much like suppressing the lich’s own magic. After all, for the most part, if you have unimpeded access to a lich’s phylactery then you can probably destroy it anyway, so it doesn’t make a whole lot of difference and seems more appropriate that way.
The real question, to me, is whether suppressing rejuvenation at the time of the lich’s destruction prevents the trigger altogether, or if it only delays it until the magic-suppression ends or is removed. Rules-as-written, it would seem to me that it’s a one-shot deal, based on the word “when.” If they had written it with “if” instead (as in, “if the lich is destroyed”), then I would go the opposite way on that. But the rules-as-written approach here seems somewhat dubious to me, on the basis that we are hanging a lot of weight on the choice of “when” over “if” for a ruleset that is not generally written with that level of care.
And narratively, I like the idea that the suppression is only good for as long as you can maintain it. It seems interesting to me to imagine having to set up some system to keep magic suppressed in the area—and an obvious future plot-hook, to have that suppression removed by scheming fools or by nosy teenagers.
But I could also see wanting to give this as an option for finishing a campaign, so that you have this epic battle wherein you have to try to make sure the lich is finished while inside the antimagic field (which would be fiendishly difficult) or else it will just reform (assuming here that for plot reasons the phylactery is inaccessible or undiscoverable).
So I think in large part it depends on how you want to run your campaign.
Best Answer
I've found no restrictions of precisely where a lich must keep its phylactery. For example, the Bestiary's lich entry mentions no restrictions nor does Undead Revisited (2011), this latter saying, "Once the soul has been safely transferred over [to the phylactery], the phylactery is then hidden through means cunning and wise," yet not saying that the phylactery must be, for example, within 1 mile of the lich or on the same plane as the lich.
Just to be sure, I made a good faith attempt to confirm the whereabouts of a few liches' phylacteries. Without giving away too much, I only tracked down a few phylacteries: two liches keep their phylacteries in rooms conveniently near where the PCs will typically encounter the liches; another keeps its phylactery secreted within its own body, which is gross and sort of confusing; a fourth just up and buried its phylactery 50 ft. down and, like, a mile or so away from where the PCs are expected to encounter it, its text going so to note that this is not a particularly secure hiding place; a fifth is rumored to have its phylactery hidden beneath a nearby settlement, and, if such rumors are true, the exact location goes unsaid; and a sixth split its phylactery into three parts and scattered them widely, intending its followers unify the pieces so that it could reform.
(I used the list of liches on this page as a guide, and sources I checked included but weren't limited to the Pathfinder Campaign Setting, Gods and Magic, Inner Sea Primer, Shadows Gallowspire, Sins of the Savior, and Thousand Fangs Below.)
Thus, to be clear, while no published lich I found seems to hide its phylactery on a different plane, nothing I've found say a lich can't keep a phylactery on a different plane. However, a lich that keeps its phylactery on a different plane but is itself unable to muster a gate spell or another means of precision planar travel will typically be at the mercy of the inaccuracy of the spell plane shift.
That is, the plane shift spell forces a lich that reforms on a different plane and that seeks revenge against those who downed it to take the fairly significant risk of arriving 5d100 mi. away from its destination when it returns to its native plane! Not knowing where its plane shift spell will deposit it still shouldn't prevent an extremely confident or paranoid lich from storing its phylactery on a different plane, but that risk may deter otherwise overconfident or supremely cautious liches from doing so.
War Story: D&D 3.5 also lacks such restriction, and, because of this, this DM had during one campaign a particularly paranoid demilich hide its phylactery on a plane it created itself that could be reached only from a different crystal sphere than the one where the campaign normally took place. (The phylactery was also guarded by, among other creatures, a phane.) Needless to say, the players were very pleased with themselves when they finally destroyed that phylactery!