Gaslamp Fantasy (also Gaslight Fantasy or Gaslamp/Gaslight Romance) is the magical equivalent to Steampunk in the array of Setting Aesthetics, combining Victorian Era Earth aesthetics (if not set during that time completely) with wide-spread magic - usually in a Dark Fantasy or Heroic Fantasy level. The term is rare, having been coined by the webcomic "Girl Genius" to make itself stand out better from the Steampunk crowd, but it is a recognized trope, and has come to be applied retroactively to many existing works of "steampunk" or "gothic horror".
The key difference between gaslamp fantasy and steampunk is that steampunk focuses on alternate developments in technology (and need not have any magic at all), while gaslamp fantasy focuses on supernatural elements (and need not have any technology that didn't actually exist). Yet, the two can overlap, especially with Magitek and in settings that make use of what TVTropes describes as "Phlebotinum-Induced Steampunk" - the addition of some fantastical element or other that makes steampunk technology actually viable.
Girl Genius created the term because its creators wanted to avoid confusion with a comic named "Steampunk", but also because it was focused on more than just advanced steam power, was not a dystopian-type "Punk" work, despite having similar aesthetics, and is heavy on mad science to the point of being basically a magical version of 19th/20th century Earth that was pretending it was actually a scientific world.
List of Gaslamp Fantasy Games
- Blades in the Dark
- Broken Gears
- Call of Cthulhu - Cthulhu by Gaslight subsetting
- Castle Falkenstein
- Deadlands (Gaslamp Fantasy/Screampunk/Cattlepunk hybrid)
- GURPS - GURPS Goblins and GURPS Steampunk 1: Settings and Style
- Mage: The Ascension - This is the Reality Paradigm of the Sons of Ether faction.
- Magic: The Gathering - The plane of Ravnica has an aesthetic (especially in the areas controlled by the Izzet League) that falls under either this or Dungeonpunk.
- Masque of the Red Death (Gaslamp Fantasy/Gothic Horror)
- Unhallowed Metropolis (Gaslamp Fantasy/Screampunk hybrid)