I won't pretend to be a lawyer, or even to know all the details of what I'm talking about. Even so, being a modder for a few years can give an insight into what you can get away with.
So lets begin.
Firstly your mod is probably (although not always) illegal if:
- It can be played without buying the original game.
- You try to sell it or profit from it.
- You have ripped someone's work without permission.
- The mod is based on a book without the author's permission.
- The mod is based on a film or series without permission of the studio/company who made it.
Now that bit is over with, read on to see if something you thought you could get away with may actually be wrong.
Anybody can make mistakes when trying to create something. I've done it a few times, I'm sure a few other people around here have. So here are a couple of the common thoughts which aren't actually right at all.
First off, merely not profiting from something does not make you immune from prosecution. If you use some professional, sold music in your mod (even if you paid for the CD) without a proper distribution licence it can get very unpleasant, and the fine is often more than a licence would be.
The Website Disclaimer
I have seen dotted around, specifically on DBZ mod sites, things like the following:
For controversial reasons, if you are now, or ever once were, in any way affiliated with FUNimation or any other related group you CANNOT enter this web site, or any of it's related features, including but not limited to, FTP, HTTP, eMail, etc.. If you enter this site in violation of the above terms you are in violation of code 431.322.12 of the Internet Privacy Act signed by President Bill Clinton in 1995 and therefore CANNOT threaten our ISP(s) or any person(s) or company storing these files, and cannot prosecute any person(s) affiliated with this page, including but not limited to family, friends or individuals who maintain or enter this web site.
This, despite anything you may have heard, means absolutely nothing to the people you target it at.
The Internet Privacy Act 1995 does indeed make it illegal for the people mentioned to enter the site, providing they are not collecting evidence for a legal case. If they were that particular law is discounted and full access can be taken at a public level (i.e. they can't get into your FTP but anything the public can see, they can see). A court order could give them full access.
Also, this would only even begin to work if the site is hosted in the USA where the law is applicable. Host it in Finland for example and it means nothing.
It's Public Domain
Just because the public can see something does not make it public domain. Because something is on the internet does not mean you can copy/paste it freely. Look in the How to Get Away With Stuff section (next) for help on this.
[page=How To Get Away With Stuff]
Of course, breaking laws for a mod is pretty damn stupid to start with, so don't do it. However, if you really must have that picture of Gohan or that uzi model is too good to miss out on then this should help keep you legal.
Get A Lawyer
Even if it's just your family lawyer, make sure one is available. Ask them if you're unsure on anything, and please don't take this guide as being definitive, I can almost guarantee there is at least one big mistake in here. Your lawyer will come in useful for proving you did things, signing forms, witnessing licencing if you ever go that far...
Get In Touch
To begin with, find the copyright holder and ask for permission to use their stuff. Tell them what it's for (your mod, basic details, link to modDB profile) and you can often get a licence to use something for nothing more than giving them a line in the credits. There are certain ways to go about this:
First, check for copyright. If there is no copyright holder information you're still not safe. Look for the name of the creator and get in touch with them. If you can't do that you're still not out of the water. Email the site operator and ask for contact details. If at any point you recieve a "No, you can't use it" then just drop it right there.
If no details are available or you simply can't get in touch with the creator you can use the content, but you must keep your messages and his replies and get a legally valid datestamp on them. One method is printing them out, and mailing them to yourself. Do not under any circumstances open the envelope, since the postmark is legal proof of date. You will need this as evidence you attempted to contact the copyright holder through more than one way. You will also need to say quite clearly wherever the content is used that if the copyright holder contacts you then they can have the content removed regardless of consequences. You must also say several attempts at contacting them were made (this is where your envelope and lawyer come in).
If you use a lot of stuff from one place and your mod is really popular (don't do this for a simple free-time mod, please. I really mean it.) then it may be worth getting a licence from whoever's behind what you're using. If you use a lot of music from Linkin Park in your mod, for example, approach their record company with your lawyer (If you don't have one then get one) and see how much a licence for the music would cost. For big corporations or groups this could run into a lot of money, but if you have a big mod licencing maybe one track as your title one should just border affordable, and some in-mod pimpage and a big mention in the credits can chop the prices quite a bit.
If you want to make a standalone modification, it could get interesting since unless the engine is open source you're going to have to licence yourself a game engine. A licence for the Unreal engine for non-corporate purposes is still an impressive sum, so only go standalone if either it's free or you're bordering loopyland.
If you want to join the crowd and make a DBZ mod or a Star Trek mod (Not literally, I mean TV/Film) then give it up right now. The corporations will come down on you like a ton of bricks if they find you, and licences for film or series franchise are literally hundreds of thousands. Don't do it, we hate to see mods go down like that.