Is there a benefit to having one common skeleton for all characters?

In my game I plan on having some human space marines, and a variety of monsters. (Think DooM in a way)

For the humans I plan on having the skeleton be similar to the one used in the UE4 mannequin.

A lot of the monsters would have similar skeletons but very different bind poses and proportions, and maybe a few extra things here and there like giant claws, or no arms, etc… Would it be better to just have a separate skeleton per monster or try to have a common skeleton for as many characters as possible, and let some of the bones go unused?

I was looking at UT and the skaarj have a bunch of random extra stuff for hair and tails that go unused in normal human characters. I guess the benefit here is being able to reuse animations between all characters, but otherwise I can see it becoming a huge pain in the future as you add more and more random complex characters. I don’t see myself reusing some random demon’s animation for my space marine and vice versa.

The more you can reuse your assets in general the better. Skeletons are a big plus on this, as rigging, animating, and the likes can be very tedious/time consuming. However, don’t work against your self. Unreal is a pretty basic game in terms of animations. You’re running around so fast that you don’t really need to have crazy animations for everyone, so sharing one skeleton allows them to pass along the same animations to every “race” without redoing all the animations. Great for production.

But if you’re animating a spider versus a marine in something of more controlled gameplay, unless your spider is humanoid, don’t bother trying to keep the skeletons the same as you’ll be spending more time working around the idea of a universal skeleton, and it’ll be worse for production and quality. So while it can be very useful to use the same skeleton, especially for something that doesn’t change much (which humans and aliens in UT really don’t), it’s not something that should be applied to everything.

Is there any considerable perf benefit, like maybe in terms of memory or CPU usage? I have a few monsters that can easily share the basic human skeleton and heirarchy. I’m hoping to have many of these guys on screen at once.

If there isn’t much perf benefit I’ll stick to doing what’s easier and not trying too hard to share skeletons between most of the monsters.

Reviving this, are there considerable performance benefits of having one skeleton over unique skeletons for many characters?

As some have stated “RAM is a thing”, and that more, different things to keep track of and evaluate is more costly in general.

The Animation Sharing plugin helps manage large crowds that have similar animations: Animation Sharing Plugin | Unreal Engine Documentation