Thoughts on my homebrew formula for creating undead and magic items

[preteriteeggnog]

Creating magic items, golems and undead costs very rare resources in units of the power gained from using horrid necromancy to extract power equivalent to 1 human soul. It is possible to gain power in less evil ways but they are less easy. Costs less than or equal to 0.05 of a soul can be paid in valuable gems.

Creating an undead creature or golem worth some amount of Points costs:

Souls = 10000000000^((600 + Points)/1000)/100000000

This means that:

A 0 points creature costs 0.01 souls.
A 100 points creature costs 0.1 souls.
A 200 points creature costs 1 soul
A 300 points creature costs 10 souls
A 400 points creature costs 100 souls
A 500 points creature costs 1000 souls

Magic items are costed in a similar way.

Secondly, actually controlling golems and undead permanently requires creating a magic item to bind them. These magic items require attunement and one can only be attuned to three items at a time or something.

A golem controlling amulet can generally only control and order one golem at a time. If the amulet is broken the golem goes berserk. The amulet is included in the cost of the golem.

An undead controlling amulet that controls some Amount of undead costs:

Souls = 10^(Amount)/1000

Therefore:

Controlling 1 creatures costs 0.01 souls
Controlling 2 creatures costs 0.1 souls
Controlling 3 creatures costs 1 soul
Controlling 4 creatures costs 10 souls
Controlling 5 creatures costs 100 souls

For the first 30 days after creating undead they will not harm the creator.

In the setting almost no one sells souls in exchange for cash. It is too valuable for making magic items, casting very powerful magic spells, etc....

These rules prevent people creating very powerful undead by making creating undead very expensive.

These rules avoids people directly controlling hordes of zombies and bogging down combat. They can create hordes of zombies and using certain techniques direct them in very general ways but they are a very much imprecise tool and controlled by the GM.

So what are peoples' thoughts?

[ericthered]

I think your formulas could use some simplification and clarification.

I think the base of 200 point creations for a single soul is a little high.

Exponential soul cost works well: I approve. The curve is very steep though.

Controlling is a little lower than I would have thought -- the exponential curve seems especially steep there.

[preteriteeggnog]

There is one thing I forgot to mention. Typically before an evil necromancer makes a 200 point creature he will extract the soul of his victim and then use that soul energy to animate the same corpse. So, in practise creating a 200 point creature is effectively free as long as one is willing to be really evil.

The extreme limitation on controlling lots of zombies is to prevent PCs bogging down combat with a horde of undead. I plan on introducing plenty ways to handle hordes of undead that aren't directly puppeted by players such that an evil necromancer could still direct a horde of undead to attack a village. However, the necromancer couldn't carefully guide the horde through a dungeon. The necromancer would need a bunch of helper necromancers (maybe some intelligent undead sergeants that he raised) for that.