Medium Undead, Any Evil Alignment
Armor Class 21 Robes of the Archmagi
Hit Points 135 (18d8 + 54)
Speed 30 ft.
STR
11 (+0)
DEX
16 (+3)
CON
16 (+3)
INT
20 (+5)
WIS
14 (+2)
CHA
16 (+3)
Saving Throws CON +10, INT +12, WIS +9
Skills Arcana +19, History +12, Insight +9, Perception +9
Damage Resistances Cold, Lightning, Necrotic
Damage Immunities Poison; Bludgeoning, Piercing, and Slashing from Nonmagical Attacks
Condition Immunities Charmed, Exhaustion, Frightened, Paralyzed, Poisoned
Senses Truesight 120 ft., Passive Perception 19
Languages Abyssal, Celestial, Common plus up to five other languages, Deep Speech, Infernal, Undercommon
Challenge 21 (33,000 XP)
Proficiency Bonus +7
Traits

Legendary Resistance (3/Day). If the archlich fails a saving throw, it can choose to succeed instead.

Rejuvenation. If it has a phylactery, a destroyed archlich gains a new body in 1d10 days, regaining all its hit points and becoming active again. The new body appears within 5 feet of the phylactery.

Spellcasting. The archlich is an 18th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 20, +12 to hit with spell attacks). The archlich has the following wizard spells prepared:

Cantrips (at will): mage hand, prestidigitation, ray of frost

1st level (4 slots): detect magic, magic missile, shield, thunderwave

2nd level (3 slots): acid arrow, detect thoughts, invisibility, mirror image

3rd level (3 slots): animate dead, counterspell, dispel magic, fireball

4th level (3 slots): blight, dimension door

5th level (3 slots): cloudkill, scrying

6th level (1 slot): disintegrate, globe of invulnerability

7th level (1 slot): finger of death, plane shift

8th level (1 slot): dominate monster, power word stun

9th level (1 slot): power word kill

Turn Resistance. The archlich has advantage on saving throws against any effect that turns undead.

Robes of the Archmagi. 

  • If you aren’t wearing armor, your base Armor Class is 15 + your Dexterity modifier.
  • You have advantage on saving throws against spells and other magical effects.
  • Your spell save DC and spell attack bonus each increase by 2.

Ring of Protection. You gain a +1 bonus to AC and saving throws while wearing this ring.

Staff of Power. This staff can be wielded as a magic quarterstaff that grants a +2 bonus to attack and damage rolls made with it. While holding it, you gain a +2 bonus to Armor Class, saving throws, and spell attack rolls.

Power Strike. When you hit with a melee attack using the staff, you can expend 1 charge to deal an extra 1d6 force damage to the target.

Spells. While holding this staff, you can use an action to expend 1 or more of its charges to cast one of the following spells from it, using your spell save DC and spell attack bonus: cone of cold (5 charges), fireball (5th-level version, 5 charges), globe of invulnerability (6 charges), hold monster(5 charges), levitate(2 charges), lightning bolt(5th-level version, 5 charges), magic missile(1 charge), [Tooltip Not Found](1 charge), or wall of force(5 charges).

Retributive Strike. You can use an action to break the staff over your knee or against a solid surface, performing a retributive strike. The staff is destroyed and releases its remaining magic in an explosion that expands to fill a 30-foot-radius sphere centered on it.

You have a 50 percent chance to instantly travel to a random plane of existence, avoiding the explosion. If you fail to avoid the effect, you take force damage equal to 16 × the number of charges in the staff. Every other creature in the area must make a DC 17 Dexterity saving throw. On a failed save, a creature takes an amount of damage based on how far away it is from the point of origin, as shown in the following table. On a successful save, a creature takes half as much damage.

DAMAGE TABLE.

10ft or closer = 8x the number of charges in the staff

11-20ft = 6x the number of charges in the staff

21-30ft = 4x the number of charges in the staff

Arcane Grimoire (Very Rare). While you are holding this leather-bound book, you can use it as a spellcasting focus for your wizard spells, and you gain a bonus to spell attack rolls and to the saving throw DCs of your wizard spells. The bonus is determined by the book's rarity.

You can use this book as a spellbook. In addition, when you use your Arcane Recovery feature, you can increase the number of spell slot levels you regain by 1.

Actions

Paralyzing Touch. Melee Spell Attack: +12 to hit, reach 5 ft., one creature. Hit: 10 (3d6) cold damage. The target must succeed on a DC 18 Constitution saving throw or be paralyzed for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Staff of Power. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 4 (1d6) bludgeoning damage, or 7 [rollable](1d10);

Legendary Actions

The archlich can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. The archlich regains spent legendary actions at the start of its turn.

Cantrip. The archlich casts a cantrip.

Paralyzing Touch (Costs 2 Actions). The archlich uses its Paralyzing Touch.

Frightening Gaze (Costs 2 Actions). The archlich fixes its gaze on one creature it can see within 10 feet of it. The target must succeed on a DC 18 Wisdom saving throw against this magic or become frightened for 1 minute. The frightened target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a target’s saving throw is successful or the effect ends for it, the target is immune to the archlich’s gaze for the next 24 hours.

Disrupt Life (Costs 3 Actions). Each non-undead creature within 20 feet of the archlich must make a DC 18 Constitution saving throw against this magic, taking 21 (6d6) necrotic damage on a failed save, or half as much damage on a successful one.

Lair and Lair Actions

An Archlich’s Lair

An archlich often haunts the abode it favored in life, such as a lonely tower, a haunted ruin, or an academy of black magic. Alternatively, some archliches construct secret tombs filled with powerful guardians and traps.

Everything about a archlich’s lair reflects its keen mind and wicked cunning, including the magic and mundane traps that secure it. Undead, constructs, and bound demons lurk in shadowy recesses, emerging to destroy those who dare to disturb the archlich’s work.

An archlich encountered in its lair has a challenge rating of 22 (41,000 XP).

Lair Actions

On initiative count 20 (losing initiative ties), the archlich can take a lair action to cause one of the following magical effects; the archlich can’t use the same effect two rounds in a row:

  • The archlich rolls a d8 and regains a spell slot of that level or lower. If it has no spent spell slots of that level or lower, nothing happens.
  • The archlich targets one creature it can see within 30 feet of it. A crackling cord of negative energy tethers the archlich to the target. Whenever the archlich takes damage, the target must make a DC 18 Constitution saving throw. On a failed save, the archlich takes half the damage (rounded down), and the target takes the remaining damage. This tether lasts until initiative count 20 on the next round or until the archlich or the target is no longer in the archlich’s lair.
  • The archlich calls forth the spirits of creatures that died in its lair. These apparitions materialize and attack one creature that the archlich can see within 60 feet of it. The target must succeed on a DC 18 Constitution saving throw, taking 52 (15d6) necrotic damage on a failed save, or half as much damage on a success. The apparitions then disappear.
The_Unchosen_One