Dm help: toning down a lich

[Desteplo]

I get it. They're a high level creature
-how could I tone down the lich to match a lvl 5-6 party?

-should I keep the legendary actions?
-5th lvl caster?
-tone down D.C. To 14? And dmg by a few dice?
-way less health

[Draken]

I get it. They're a high level creature
-how could I tone down the lich to match a lvl 5-6 party?

-should I keep the legendary actions?
-5th lvl caster?
-tone down D.C. To 14? And dmg by a few dice?
-way less health

Take a Mage NPC and give it the appropriate features (legendary actions, etc).

[JackPhoenix]

How big is the party, any magic items? How challenging should the encounter be, and should the "lich" be alone, or with minions? Any specifics on the intended encounter? Is it the last battle in a long dungeon, where the party will have some of their abilities expended, or will they be at full strength? It's hard to say how to balance something if we don't know the important details.

[Specter]

Take a pre-made wizard (level 10 I'd say) and give him the undead traits and resistances.

[DivisibleByZero]

Take a Mage NPC and give it the appropriate features (legendary actions, etc).

This.
The Mage is CR6. Just add flavor (read: lich stuff with lower DCs) and you've got yourself a lower CR lich, probably at about CR7 or so, which is a tough but winnable fight for a lvl5-6 party.
And honestly, it's a cake walk if the party is DPS heavy unless you boost his HP a bit.

[lunaticfringe]

Take a pre-made wizard (level 10 I'd say) and give him the undead traits and resistances.

This would be my suggestion. Reskin and slapping on traits from other Mooks is money. Also custom spell lists are great for themed casters, you don't have to limit yourself to a specific class list either.

[Findulidas]

This.
The Mage is CR6. Just add flavor (read: lich stuff with lower DCs) and you've got yourself a lower CR lich, probably at about CR7 or so, which is a tough but winnable fight for a lvl5-6 party.
And honestly, it's a cake walk if the party is DPS heavy unless you boost his HP a bit.

I think this is much better than creating a PC and then converting it. The monsters are made to be fought. The classes not.

[SharkForce]

i wouldn't give legendary stuff. the lich in the monster manual is legendary. if that lich set it's mind to the task, it could probably bring entire kingdoms to their knees unless those kingdoms have the equivalent of a powerful adventuring party available to them.

the CR 6 mage, even with undead features, not nearly as much of a threat. he's pretty nasty (and being a lich, you probably will give a bunch of undead henchmen to support), but he's not going to churn out hordes of mummies and wights or anything like that. or even ghouls for that matter.