One thing I've noticed being a very common thing to complain about is that the NPC witches always end up lagging the game whenever they first appear on a lot, and this also happens in my own game as well.

However this hasn't really been the case for any playable witches I have, regardless of alignment so I'm somewhat curious as to why there's this discrepancy in how they act.

So yeah I'm mostly just curious if anyone knows precisely why the NPC witches always seem to cause so much lag when they appear.

I do believe it's the forming the 'apparition' stage where a witch is generated and the form it takes-either good or bad.
But I do wish there was a way to eliminate it besides by banning them off the lots.

Witches can be cool. I just wish they weren't so graphics heavy.

If they are created new, the Skin Overlay is extremely demanding, just like with overheating. Creation of a new Spectral Cat character is also hard.

So a mod getting rid of the skin overlay should also get rid of the lag?

I use a mod to get rid of the skin overlay and it does *not* fix the lag.

Most mods that "get rid of" the skin overlay, or modify/tone it down tend to just be the skin overlay sans the texture, so the witch still has the overlay applied, but the texture is invisible. You'd need to find a mod that stopped the skin overlay from applying in the first place (not sure there is one?)

There are also some visual effects with the witches, and it's possible those count in, too.

Anything that takes a bit of extra brain power for the computer can cause lag (especially if it includes skin changes/skin overlays, transitions between sim states, effects, spawning in new sims, and similar, plus anything that requires dipping into heavy resources - CAS resources tend to be a bit heavy). How much lag depends on the computer, and also a bit on the computer itself, and how busy the computer already is with managing the rest of the lot (managing other sims, effects, CC load, size of the lot, etc.)

If you use defaults the game hasn't loaded in before, the game may also spend some extra time figuring out the details there. Same if it's a new computer/game bootup cycle from the previous time you played (notice how CAS and such always loads a bit slower after a recent bootup?).

Ah, ok. That makes sense. So it might be the overlays even though I have a mod to make my witches look normal.

My game hangs whenever a witch enters a lot, doesn't matter if it's the high witch. I think it's something to do with the broom flying animation. My game also does this if a werewolf walks onto a lot (residential or community) regardless of whether the sim is currently transformed or not. I've never been quite sure why this happens but it's an annoyance I've had to learn to deal with.

I think it's just that loading witch sim + witch skin overlay + witch magic glowy effects + broom + spectral cat + cat glowy effects, all at once, is a good bit more taxing than loading in one normal sim arriving at the lot

And of course, the high witches also immediately cast a spell that affects the weather, which is further effects to load right afterwards

It happens even without RPC mod, it did for me and most every youtuber online that you can watch play the sims 2. In fact I'm just glad that witches don't usually crash the game period. it is annoying for me but as long as the game dosen't crash because of it it's tolerable to deal with in my own opinion

as for why? well witches do come on a brookstick, and with a different kind of cat and can change the weather so maybe that all combined into one contributes to the lag?

I always assumed it was the glow. I ban them automatically from all community lots for this reason...