Came up with a bunch of good names for future games --- so good that they were already taken, somewhere at some time.
And because we’re such a litigious society, people will sue over even partial names.
I remember getting a threatening letter because we had a technology in Galactic Civilizations II called “Space Marines” and that they had a trademark on that name. We renamed it to Stellar Marines (sounds better anyway).
In recent times, companies have had to resort with coming up with fewer main names “Call of Duty” or “Total War” and then come up with a sub-title in order to have sufficient uniqueness (and of course, even that doesn’t always keep the super-litigious from trying to find a way to cash in).
Hence, I was afraid of calling our first fantasy game “War of Magic” because god knows, there’s probably some game some where called that so we had to call it Elemental: War of Magic. Luckily, Sins of a Solar Empire: Rebellion is probably safe… 