So.... Lets say a lich has his phylactery stolen and placed somewhere.  For whatever reason the person who stole it didn't want to destroy it outright, but instead wanted to use it for leverage over the lich.  Would the lich be able to sense where his Phylactery is?  

The rules/lore for Lichs is pretty inconsistent and has changed a lot over the years, so I would want to discuss lore/rules pertaining to 5e.

Thanks Adventurers! 

I don't think a lich has an innate ability to keep track of its phylactery. It would know where it last placed the phylactery and likely would ward the area and maybe setup a permanent Clairvoyance. If it realizes that the phylactery has been stolen the lich would likely track it down post haste via Locate Object. 

A smart lich would certainly do everything it could to protect and keep track of its phylactery as a crucial part of their continued existence.

Well locate object would only work if it is really close to you... So if it was whisked away before the lich could react it would be plausible.  

Although couldn't the lich just kill himself and resurrect close to his phylactery to figure out where it is?  

Good point regarding locate object. There's probably not a good way to track down the phylactery unless the lich knows who took it.

I suppose if he was desperate enough to get the phylactery back he could try that. It would be incredibly risky though. I think it's more likely that the lich would feign subservience to whoever has the phylactery to keep them from destroying it, biding its time until it can strike and reclaim the phylactery.

What about when he resurrects.  Is he particularly vulnerable while he is coming back to life?  I know the process takes a bunch of days (1d10) but is this an animated process or does he just sort of materialize once he's resurrected?  

If you steel the phylactery and place it in a Bag of Holding, can a Lich find it?   The phylactery is now on another plane of existence.
Also, if the Lich dies s/he reforms within 5' of the phylactery, but if the phylactery is INSIDE a bag of holding the Lich is now stuck inside a bag of holding.  Correct?

Liches don't appear to have an "innate" sense of their phylactery, but they are mega-powerful wizards so they have every tool a high level wizard has at his/her disposable.
And said Lich will probably rain fire from the sky to find it's location.

As for killing itself to reform.  It doesn't state if the body grows over the 1d10 days or if it just appears fully formed after that delay.  It does say it regains all it's HP and becomes active again.

Isn't there a way to mark things and summon them at will?  I seem to recall a spell like that.  

Anyways, this is kind of a niche area that the rules don't cover. The MM is meant to cover the most likely / commonly encountered scenarios, not one that's unusual. If you want the lich o have access to the phylactery for some reason, then they have the ability. Especially since we're talking spellcasters. That said, it makes perfect sense for, say, a warlock-based lich to not have any appropriate ways to sense their phylactery if their Patron didn't want them to have one. #notallwizards

A lich could, in theory, cast and use the instant summons spell if the phylactery is small enough.

Quote from VillainTheory >>

A lich could, in theory, cast and use the instant summons spell if the phylactery is small enough.

Also, anyone who steals from a Lich is probably going to cast at least half a dozen "Dispel Magics" on it.
They either do that or they deserve the inevitable horrific death.

Well, as a background plot point, having the evil Death Knight / Oathbreaker npc evil overlord type blackmailing the lich into service would work.

To be fair there's a lot about things like this are left out on purpose by the creative teams. Like many things in D&D it is much less "How does it work?" and more like "How do you want it to work?"

Whether they sense the phylactery, how they recover from death, what happens if X scenario - the answers to these are all your preferences and how you want it to work. Think more about which answer is better for your specific campaign than generating a catch-all answer.

Ultimately speaking, you can have it work differently between different liches. Not everyone is going to reach the goal of this lichdom the exact same way.

Yes but there is a difference between rules and lore.  A DM can always bend the rules and just say "because I said so" but if it violates the fundamental lore surrounding a creature then it comes across as lame and not well thought out.  I just wanted to make sure that in the context of Lich lore they could be separated from their phylactery and they didn't have some sort of tether to it like it was an extension of their body or something.  From the answers above it seems that most are in agreement that yes it would be hard and unlikely, but it is in the realm of possibility.

Outside of D&D (because real-world lore of what we now call lich has been around a very,very long time) the lich attains their immortality by placing part or all of their soul inside the phylactery so when the body dies the soul does not and the mind returns to the phylactery where the lich can reform their body after a time. The life of a lich is not in the body but the phylactery and so destroying it destroys the lich and the lich will always know where their phylactery is and who holds it, sometimes even influencing the holder. How much of this crosses into D&D I cannot say having never encountered a lich in any campaign yet.

However you miss my point: a DM is not just about rules they create the lore as well. There is no publishing that says "this is how Lichs are in the world of D&D" there is a basic idea and some stats and it's up to the DM to see how the lich fits into their story narrative and in what way. Again, what you have work for one lich in your story may not apply to another because ;lichdom can be sought through different means even if similar. One lich may have such a connection that they know instantly if the phylactery is touched by another being, while another doesn't. Neither breaks the lore. You can also have the phylactery be something small, or big, or be a place instead or even a demiplane - the quest then being how to trap them in that demiplane after defeating it. All work within the lore, because A, that's the point, and B, the DM makes the lore.

D&D may feature campaigns with lore but ultimate D&D overall has no set lore - you make the lore.

@Cyb3rM1nd  fair enough.  Thanks for the input.

If I was a lich, I would get myself killed or kill myself, revive near the phylactery, and take it back.

Yes, just like this thread.

a Lich would know where his Phylactery is cause the lich is the one who makes the Phylactery

This is a super old thread, but the OP (me) was asking if the phylactery was stolen and hidden with the Lich automatically know where it was.  If a lich can't find his Phylactery he might be much more cautious about dying and being resurrected in a vulnerable place.  

I would say he does.