How many undead of each type can you control at one time?

Question

With a 20 wizard necromancer, all magic items allowed (with the exception of sentient items) with the three attuned as usual, by RAW:

How many undead can you maintain control over with a 100% success rate at the same time? I want to exclude Finger of Death, and undead created by your own undead — just direct ownership.

I'd like to know how many of each tier of undead I can control. So from highest power to lowest power undead, in terms of CR, how many of each can I control? For example: mummies before ghasts, before ghouls, before zombies, etc. Meaning, if you could control 2 mummies or 4 zombies, take the mummies first, then move down spell slots.

Answer 1

I'm assuming here that your DM does not allow you to "cheat" by taking long rests more than once every 24 hours.

Your magic items are a Tome of the Stilled Tongue and 2 × Pearls of Power.

Every day, you have the following spell slots you can use to make or control undead:

9th level: 1 + 1 from Arcane Recovery + 1 from Tome of the Stilled Tongue = 3

8th level: 1

7th level: 2

6th level: 2

5th level: 3

4th level: 3

3rd level: 3 + 1 from Signature Spell + 2 from Pearls of Power = 6

Day 1:

• 3 × 9th level Create Undead = 6 mummies
• 1 × 8th level Create Undead = 2 wights
• 2 × 7th level Create Undead = 8 ghouls
• 2 × 6th level Create Undead = 6 ghouls
• 3 × 5th level Animate Dead = 18 skeletons
• 3 × 4th level Animate Dead = 12 skeletons
• 6 × 3rd level Animate Dead = 12 skeletons

Total: 6 mummies, 2 wights, 14 ghouls, 42 skeletons

Day 2:

• 6th, 7th, 8th and 9th level spell slots are used to reassert control over mummies, wights, and ghouls
• 6 × 3rd level spell slots and 3 × 4th level spell slots are used to reassert control over 42 skeletons
• 3 × 5th level spell slots are used to animate 24 skeletons

Total: 4 mummies, 2 wights, 14 ghouls, 66 skeletons

Day 3 and onwards:

• 6th, 7th, 8th and 9th level spell slots are used to reassert control over mummies, wights, and ghouls

• 6 × 3rd level spell slots, 3 × 4th level spell slots, and 3 × 5th level spell slots are used to reassert control over 66 skeletons

Total: 4 mummies, 2 wights, 14 ghouls, 66 skeletons

Answer 2

Well, it depends on the spells you used and the kind of undead, but if we're talking about the structure you're specifying... rather infinite? The given the casting time on create undead is 1 minute, and targets 3 corpses to reanimate/control for 24 hours with complete success and that you have, at the 20th level, then six mummies, six wights and forty-two ghouls for a human necromancer with an 8-hour long rest over the course of a day. For an elf? Twelve mummies, Twelve wights and eighty-four ghouls over the course of a day, because of the shorter long rest (thanks, trance). But that's just create undead, alone. For animate dead you target a extra creature thanks to Undead Thralls, your 6th level Arcane Tradition feature. Plus you can regain three 5th level slots and one 4th level slot on a short rest once, and regain that on a long rest. Given the knowledge that a short rest is 1 hour and a long rest is 4 hours for an elf and 8 hours for everyone else, as an elf you could raise 210 zombies in a single day. That's 76,650 zombies made in a year. A plenty large enough army to conquer a small country. Nevermind link because that's just crazy and your DM will send all sorts of Paladin Heroes with minmaxed stats after you.

Answer 3

Honestly you can get well into the 100s if you cheese with wights since they can control undead. If you use all other spell slots on animate dead that is.