The "Dungeon Master" example is a good example of how dangerous it can be to reuse a name, though. And no, I really wouldn't recommend such a thing.
To begin with, there's a on FTL's original box as well on the Chaos Strikes Back box, which marks the name as an unregistered trademark in the USA. This allows them to sue you, even if they didn't ® the title as a mark. You can register a mark, it just isn't strictly necessary for its validity (the Star Trek franchise has registered trade marks for ridiculous things like the letter "Q").
Further, in the UK you could even enforce the trademark without the if you have prominently used it previously, based on the "passing off tort".
Lastly, "Dungeon Master" is a registered word mark in the EU for Nice classes 9, 16, 25, 28, and 41. This includes photographic and cinematographic apparel, DVDs and similar, anything electronic, anything made from paper or cardboard, clothing, footwear, headgear, games, sport articles, and entertainment services.
This includes not only the possibility to sue you (civil action) but infringing the mark is also criminal conduct, and it further includes "liability for disturbance" which means that someone selling your trademark-infringing goods, is committing a felony, too (see Rolex vs. Ricardo).
What is truly funny is that the exact same word mark is registered concurrently by two companies, one being Wizards of the Coast (makers of D&D, 010328466), the other being Jagex (makers or Runescape, 009271008). So basically, unless Jagex challenges WotC's trade mark (which came 1 1/2 years after theirs), there are two companies who could sue you for the same word (and WotC is well-known for actually doing that, too).