This is interesting. It's a bit beyond my pay grade in terms of IP law expertise.
www.lexology.com
Basically, a German company applied for the trademark "DUNGEON" regarding a (I assume video?) game. WotC objected because it was similar to Dungeons & Dragons (I assume WoTC also owns a trademark for DUNGEON magazine).
It got appealed, but the appear failed. Interestingly, one of the factors for this was that games and video games were once niche, but are now mainstream.
I should think there are folks on this forum with a much stronger grasp of the concepts involved than me.

Wizards win a game-changing victory in Dungeons and Dragons
A recent decision by the General Court of the European Union Intellectual Property Office (EUIPO) on the effective scope of trade mark rights will…
Basically, a German company applied for the trademark "DUNGEON" regarding a (I assume video?) game. WotC objected because it was similar to Dungeons & Dragons (I assume WoTC also owns a trademark for DUNGEON magazine).
It got appealed, but the appear failed. Interestingly, one of the factors for this was that games and video games were once niche, but are now mainstream.
I should think there are folks on this forum with a much stronger grasp of the concepts involved than me.