Necromancy?

[OGDojo]

So i have a player thats playing a necromancer cleric and posed the question to me, how many undead can he control at a time? Most spells dont give a "if you cast it again it applies to the same undead" clause and if you expend like 3 spell slots at level 11 you have 6+ skeletons running around with you. And if you use all of your slots for undead it could easily be 15+. So tge question is, is there a cap? If so where can i find the rules for it?

[Hootman]

The only cap on number of undead controlled in 5e is the number you can reassert control over with your spells.

I think Animate Dead creates one (+1 per upcast) and reasserts control over four (+2 per upcast)? So, as you create more undead, you eventually have to put more slots into maintaining control, to the point where you eventually won't have any slots spare to create more until you lose some.

That's the only limit, besides your fellow players' patience.

[PallyBass]

For a cleric they will be limited by the number of spell slots they have available to use for asserting control over undead. At level 10 The cleric gains access to the "Divine Intervention" ability which can function as a super unreliable(at least until level 20) way to gain an extra casting of Animate/ Create Undead for asserting control.

If the cleric gains access to the magic item Pearl of Power they could use it to cast one additional Animate Dead spell

Unfortunately the Cleric spell list does not include the Finger of Death spell which grants a zombie permanently under their control when they kill a humanoid with it.

That's all I could think of, hope this helps!