You don't have to do that now (unless you actually *want* to).
You're right, though, the whole thing is a legal nightmare. I doubt if most of it would stand up in court.
In reality, a great many things that are claimed to be someone's intellectual property probably would not stand up in court (in the US, at least, which is my area of expertise). There are two classes of IP that folks often confuse -- trademark and copyright. Both legal structures can protect a game.
Things like trademarks are pretty straightforward -- "Traveller" is a trademark owned by Far Future Enterprises for its roleplaying game. No other roleplaying game -- and almost certainly any other game of any kind -- can use the name "Traveller". Nor can it use a name that is "deceptively similar", the touchstone being whether *consumers* are likely to confuse the similarly named game with "Traveller". So, the "Traveler" RPG would probably violate the "Traveller" trademark. However, the "Traveller" line of walking aids for blind people does not FFE's trademark (or vice versa).
Even so, it gets very complex when trademarks are claimed for character names, imaginary cities, etc. Such things are denied trademark protection unless they are found to create a link in the customer's mind with the actual producer of the good or service. So, Harry Potter became trademarkable only when there was a series of books called "Harry Potter".
Copyrights are far more complex. You can't copyright ideas, only their expression. Like most simple statements, this is almost impossible to explain in a simple sentence. In the context of Traveller, copyright law protects the entire Traveller Book from being duplicated. Game mechanics (i.e., rolling 2d6 for attributes) cannot be copyrighted. Note that the name "Traveller" is *not* copyrightable. So, Avalon Hill could create a D-Day wargame called "The Longest Day" without infringeing Cornelius Ryan's copyrighted book.
When it comes to fictional constructs (character names, alien races and their names, etc.), the creator must first prove that the alleged infringer had access to the fictional construct. Not usually hard. But the creator must then prove that there is a "substantial similarity" between the original fictional construct and the infringing construct. Courts consider a hodgepodge of factors and predictability is low. In general, the more detailed and unique the character, the greater the likelihood that it will be protected.
The "scenes a faire" exception to the "substantial similarity" analysis is particularly relevant to fictional constructs. It denies copyright protection to material that is standard or common to a particular subject or topic. Thus a stereotyped fictional character, gadget or place is not likely protected (unless one copied the *exact* description of that character/gadget/place). So, the question is whether the construct is stereotypical to the genre. Hyperspace drives, probably yes. Aslan, maybe not.
The bottom line is that there is a tremendous difference between asserting that something is your IP and it actually being your IP. The problem is that it takes expensive lawyers to get a reliable opinion -- and even then, we don't always agree. The sensible hobbyist strategy is to pick your fights and ask for permission.
Caveat -- I'm a lawyer, but I'm not your lawyer. This is not intended to be legal advice or to create an attorney/client relationship. Heck, I could be hallucinating all this stuff. So pay a lawyer for advice that you intend to rely on.