[avar]

> When creating new works with Batman, you'll have to fastidiously avoid using any elements of the character that were introduced later, but you should be good.

Everything in your comments makes sense except this part. If this goes as currently planned Batman will be in the public domain, but not e.g. Batwoman (introduced decades later).

However, I can make my own new superhero now called Foobarman and introduce a Foobarwoman without anyone having grounds for saying I'm ripping off Batman.

So if Batman is in the public domain I'll be able to have a Batwoman. Having a female version of a character isn't per-se a copyright violation just because that path's been taken before.

Of course if I go further and actually rip off entire stories involving Batwoman I'll be in trouble.

[habitue]

> if Batman is in the public domain I'll be able to have a Batwoman. Having a female version of a character isn't per-se a copyright violation just because that path's been taken before.

I think you're making a legal argument, and I have no idea if your interpretation is what the court has already decided/will decide.

[vel0city]

IANAL (only been following IP law for a long time), but if your Foobarwoman is still substantially similar to Batwoman, you're gonna have problems. Sure, there could be some kind of female companion to Batman in your new series enabled by Batman being in the public domain, but they'll have to look different and have some kind of different story line than the Batwoman currently in the DC canon.