2) then you can't use their work. Get it out of the project.
Even in a modding/hobby situation, you're actually committing copyright infringement by distributing people's work without a licence to do so -- it's just that no one will ever sue in that situation
BTW, you will need a business (LLC, etc) if you don't already. You can also try and pay people with shares in that company instead of cash...
hmmm
Guess I better just talk to a lawyer, if that was the case, then that would mean all the effort we did without those former members who left, would be a complete waste of time.
For example, if a person did a piece of concept art, then we made a model from it, running it through the rest of the art pipeline, that might make that model useless?, if the original concept artist left?
or
if a coder scripted some code, broke it, and left, then a new coder adjusts that same code to get it working again.
That can't be right?
Under pure application of #2, that would mean, every time a person left, we'd have to purge the entire project of all their work, which would not be feasible, nore logical.
I've been operating under the assumption that if a person leaves, they primarily surrender their work to the project, meaning they joint own it, but it still remains within the project, since others will likely have built on those foundations. (There's a document in our files, which they have access to which lays out expectations and how credit will be assigned, but it's not a "contract".
Most of the time, they leave and give no specific communication as to how they want their work to be handled, none have explicitly asked that their work be removed, and my point is, even if they did, in some cases, we'd not be able to feasibly oblige.
The best I can do, is not publicly release the work, keeping it all in house.
If someone really asked all their work to be removed, the only way that could be honored, is we remove all the files they did, and then also remove them from the credits fully, as if they were never part of the project. (still not practical, but if they were malicious enough to sue, for it, we'd need to evaluate the options.)
In the past, I actually have versions of our GDD, that document exactly from whom each "concept/ idea" came from, which was signed off by each core team member at the time. Guess, that would be the closest thing to a contract that we have.
Our GDD is no longer like that anymore, since we didn't feel it necessary.
In my mind, if a person leaves, in a bad way or not, and the rest of the volunteer team decide to still consider their work as critical, and Cary out the original intentions of that author, that's an honor.
It's like if a CEO steps down and the VP is promoted, and out of respect for the former CEO, keeps the company mainly the same, honoring all the past work, growing the company, and trying to do right by that person, it would be ridiculous of the CEO to come back, and say "how dare you continue my life's work, and try to respect my assumed wishes, I'm going to sue you for defamation of character, (or whatever), because I actually intended the company to fold without me."